Watlow Electric | ANAFAZE SYSTEM 32 | User`s guide | Watlow Electric ANAFAZE SYSTEM 32 User`s guide

MLS
User’s Guide
Watlow Controls
1241 Bundy Blvd.
Winona, MN 55987
Customer Service
Phone: (800) 414-4299
Fax:
(800) 445-8992
Technical Support
Phone: (507) 494-5656
Fax:
(507) 452-4507
Email: wintechsupport@watlow.com
Part No. 11570-00. Revision 3.7
November 1995
Copyright © 1995
Watlow-Anafaze
Information in this manual is subject to change without notice. No part of this publication may be
reproduced, stored in a retrieval system, or transmitted in any form without written permission from
Watlow-Anafaze.
Warranty
Watlow-Anafaze, Incorporated warrants that the products furnished under this Agreement will be
free from defects in material and workmanship for a period of one year from the date of shipment.
The customer shall provide notice of any defect to Watlow-Anafaze, Incorporated within one week
after the Customer's discovery of such defect. The sole obligation and liability of Watlow-Anafaze,
Incorporated under this warranty shall be to repair or replace, at its option and without cost to the
Customer, the defective product or part.
Upon request by Watlow-Anafaze, Incorporated, the product or part claimed to be defective shall
immediately be returned at the Customer's expense to Watlow-Anafaze, Incorporated. Replaced or
repaired products or parts will be shipped to the Customer at the expense of Watlow-Anafaze,
Incorporated.
There shall be no warranty or liability for any products or parts that have been subject to misuse,
accident, negligence, failure of electric power or modification by the Customer without the written
approval of Watlow-Anafaze, Incorporated. Final determination of warranty eligibility shall be
made by Watlow-Anafaze, Incorporated. If a warranty claim is considered invalid for any reason,
the Customer will be charged for services performed and expenses incurred by Watlow-Anafaze,
Incorporated in handling and shipping the returned unit.
If replacement parts are supplied or repairs made during the original warranty period, the warranty
period for the replacement or repaired part shall terminate with the termination of the warranty
period of the original product or part.
The foregoing warranty constitutes the sole liability of Watlow-Anafaze, Incorporated and the customer's sole remedy with respect to the products. It is in lieu of all other warranties, liabilities, and
remedies. Except as thus provided, Watlow-Anafaze, Inc. disclaims all warranties, express or
implied, including any warranty of merchantability or fitness for a particular purpose.
Please Note: External safety devices must be used with this equipment.
Addendum for MLS User’s Guide (3.6)
Addendum for MLS User’s
Guide (3.6)
The following are changes to revision 3.6 of the MLS User’s Guide. The
changes pertain to a new power supply that is being used with the MLS.
All changes are listed below by page number. Shaded portions refer to
the actual changed text.
These changes will be incorporated in the next manual revision.
System Power Requirements (from page 10)
MLS-PM supply input
10-28 Vdc at <1 amp
MLS-AIM supply input
4.75 to 5.25 Vdc at <0.5 amp, supplied by MLSPM
MLS-PS system power supply
Input: 120/240 Vac at 0.75 amp
Output: 15 Vdc at 1.2 amp, 5 Vdc at 4 amp
Dimensions and Weight (from page 10)
MLS-PM
1.75 lbs., 1.89" x 3.78" x 6.75" (0.8 kg, 4.75 cm x 10 cm x 17
cm.)
MLS-AIM-TB
& AIM cards
1.50 lbs., 5.0" x 6.50" x 5.50" (0.7 kg, 12.5 cm x 16.25 cm x
13.75 cm.)
MLS-PS
1.2 lbs., 1.40" x 8.0" x 3.9" (0.6 kg, 3.56 cm x 20.32 cm x 9.91
cm.)
RTB
.5 lbs, 5.0’’ x 3.0’’ x 2.25’’ (.227 kg, 12.7 cm x 7.6 cm x 5.7 cm.)
MLS User’s Guide (11570-00 rev. 3.6) I
Addendum for MLS User’s Guide (3.6)
Mounting the MLS-PS (from page 23)
Follow these instructions to mount the MLS-PS.
If you use your own power supply for the MLS, please refer to the
power supply manufacturer's instructions for mounting information.
Choose a power supply that supplies a regulated 10 to 28 Vdc at 1 watt,
and isolated return line.
Mounting Environment
The MLS-PS measures 1.40" x 8" x 3.9". Leave enough clearance
around the power supply that you can remove it later.
Mounting Steps
The MLS-PS has a mounting bracket. The bracket has two screw holes
which will accept #6 or #10 screws. To mount the MLS-PS, attach the
power supply to your panel with the two screws and the power supply
mounting bracket.
II MLS User’s Guide (11570-00 rev. 3.6)
Addendum for MLS User’s Guide (3.6)
Wiring Your System (from page 24)
This section explains how to wire the components of your system.
Below is the system connections diagram reprinted here for your
convenience. (See the next page for wiring instructions.)
MLS User’s Guide (11570-00 rev. 3.6) III
Addendum for MLS User’s Guide (3.6)
Wiring Recommendations (from page 25)
This section gives general wiring recommendations.
WARNING
Never wire bundles of low power Watlow-Anafaze
circuits next to bundles of high power AC wiring.
Instead, physically separate high power circuits
from the controller. If possible, install high voltage
AC power circuits in a separate panel.
• Use stranded wire. (Use solid wire for fixed service; it makes intermittent connections when you move it for maintenance.)
• Use #18 or #20 AWG wire. Larger or smaller sizes may be difficult to
install, may break easily, or may cause intermittent connections.
• Use shielded wire. (The electrical shield protects the MLS from
electrical noise.) Connect one end of the input wiring shield to the
MLS panel's 120/240 Vac panel ground, and connect one end of the
output wiring shield to the MLS panel's
120/240 Vac panel ground. (If your system requires a different
shield configuration, contact Watlow-Anafaze for more information.)
For more information about noise suppression, see Noise Suppression.
Connecting Power and RTB to MLS-PM (from page 27)
1. Remove the temporary covers you placed on the MLS' housing.
2. Connect the power supply terminal labeled "DC COM" to the terminal labeled "GND" on the Processor Module. This terminal is DC
common; it is not frame, chassis or earth ground.
3. Connect the power supply terminal labeled "+15V" to the terminal
labeled "+V" on the Processor Module.
4. Connect the 50-pin ribbon cable to the Processor Module. Plug it in
so that the red stripe is on the left side, under TB1.
5. Connect the ribbon cable to the RTB. Plug it in so that the red stripe is
closest to screw terminal 1.
IV MLS User’s Guide (11570-00 rev. 3.6)
Contents
Overview .....................................................................1
System Diagram.................................................................. 2
Parts List .. .......................................................................... 2
Safety ....... .......................................................................... 3
Introduction................................................................5
Specifications...................................................................... 7
Analog Outputs ............................................................. 8
Digital Inputs ................................................................ 8
Digital Outputs.............................................................. 9
Miscellaneous Specifications............................................. 10
Serial Interface .............................................................. 10
System Power Requirements ........................................ 10
Environmental Specifications ....................................... 10
Dimensions and Weight................................................ 10
Expanded Parts List ............................................................ 11
MLS Processor Module Technical Description............ 11
MLS RTB Technical Description ................................. 13
MLS-AIM and AIM-TB Technical Description........... 13
MLS Cabling Technical Description ............................ 14
Installation..................................................................15
Read This Before Installation ............................................. 16
Recommended Tools .......................................................... 17
Panel Hole Cutters ........................................................ 17
Other Tools ................................................................... 17
Additional Hardware..................................................... 17
Mounting the MLS-PM ...................................................... 18
Mounting Environment................................................. 18
MLS-PM Mounting Steps............................................. 19
Mounting the MLS-AIM .................................................... 20
Mounting Environment................................................. 20
Mounting Steps ............................................................. 21
Mounting the RTB .............................................................. 22
Mounting the MLS-PS........................................................ 23
Mounting Environment................................................. 23
Mounting Steps ............................................................. 23
Wiring Your System ........................................................... 24
Wiring Recommendations ............................................ 25
Cable Recommendations .............................................. 26
Noise Suppression......................................................... 26
Wiring and Testing Your System ....................................... 27
i
Contents
MLS User’s Guide
Connecting Power and RTB to MLS-PM..................... 27
Connecting Power and Common to AIM-TB............... 28
Testing Connections ..................................................... 28
Testing Your System .......................................................... 30
MLS-AIM Test ............................................................. 30
RTB Test....................................................................... 30
PID Output Test ............................................................ 30
Outputs..... .......................................................................... 31
PID Control and Alarm Output Connections................ 33
RTB Connections.......................................................... 34
AIM Communications Failure ...................................... 35
Inputs ....... .......................................................................... 36
Input Wiring Recommendations ................................... 37
Input Scaling ................................................................. 37
T/C Inputs ..................................................................... 39
RTD Inputs ................................................................... 40
Current Inputs ............................................................... 41
Voltage Inputs............................................................... 41
Unused Inputs ............................................................... 41
Communications ................................................................. 42
Changing Communications........................................... 42
Connecting RS-232 Communications .......................... 42
Connecting RS-485 Communications .......................... 43
Recommended Wire Gauges ........................................ 45
Using the MLS............................................................47
Front Panel .......................................................................... 48
Front Panel Keys........................................................... 49
Displays ... .......................................................................... 51
Viewing Several Loops: Bar Graph Display ................ 51
Viewing One Loop: Single Loop Display .................... 52
Interpreting Alarm Display........................................... 53
Displaying, Loading, and Saving Jobs................................ 55
Operator Menus .................................................................. 56
Changing the Setpoint................................................... 56
Selecting Manual, Automatic, or Tune Control............ 56
Setup ...........................................................................59
How to enter the Setup menus? .................................... 59
How to edit a menu? ..................................................... 59
Setup Global Parameters Menu .......................................... 61
Save to Job .................................................................... 62
Load from Job ............................................................... 62
Job Select Inputs ........................................................... 63
ii
MLS User’s Guide
Contents
Job Digital Input Polarity.............................................. 64
Output Override Digital Input....................................... 64
Output Override Input Polarity ..................................... 64
Startup Alarm Delay ..................................................... 65
Keyboard Lock Status................................................... 65
Power-Up Output Status ............................................... 65
Controller Address ........................................................ 66
Communications Error Checking ................................. 66
Communications Baud Rate ......................................... 67
Allen Bradley Protocol ................................................. 67
AC Line Frequency....................................................... 67
Digital Output Polarity.................................................. 68
AIM Communications Failure Output .......................... 68
EPROM Information..................................................... 68
Setup Loop Input .......................................................... 69
Input Type..................................................................... 70
Pulse Sample Time ....................................................... 71
Loop Name ................................................................... 71
Input Units .................................................................... 71
Input Reading Offset..................................................... 72
Linear Scaling Menus ................................................... 72
Display Format ............................................................. 74
High Process Value....................................................... 74
High Reading ................................................................ 75
Low Process Value ....................................................... 75
Low Reading................................................................. 75
Input Filter .................................................................... 76
Setup Loop Control Parameters .......................................... 77
Heat/Cool Control PB................................................... 78
Heat/Cool Control TI .................................................... 78
Heat/Cool Control TD .................................................. 78
Heat/Cool Output Filter ................................................ 79
Heat/Cool Spread.......................................................... 79
Setup Loop Outputs ............................................................ 80
Enable/Disable Heat and Cool Outputs ........................ 82
Heat or Cool Output Type ............................................ 82
Heat/Cool Cycle Time .................................................. 83
SDAC Menus ...................................................................... 83
SDAC Mode ................................................................. 83
SDAC High Value ........................................................ 84
SDAC Low Value......................................................... 84
Heat/Cool Output Action .............................................. 84
Heat/Cool Output Limit ................................................ 85
Heat/Cool Output Limit Time....................................... 85
iii
Contents
MLS User’s Guide
Heat/Cool Output Override........................................... 85
Heat/Cool Nonlinear Output Curve .............................. 86
Setup Loop Alarms ............................................................. 87
Alarm Types ................................................................ 88
Alarm Delay.................................................................. 90
High Process Alarm Setpoint........................................ 91
High Process Alarm Type............................................. 91
High Process Alarm Output Number............................ 91
Deviation Band Value................................................... 92
High Deviation Alarm Type ......................................... 92
High Deviation Alarm Output Number ........................ 93
Low Deviation Alarm Type.......................................... 93
Low Deviation Alarm Output Number ......................... 93
Low Process Alarm Setpoint ........................................ 94
Low Process Alarm Type ............................................. 94
Low Process Alarm Output Number ............................ 94
Alarm Deadband ........................................................... 95
Loop Alarm Delay ........................................................ 95
Manual I/O Test .................................................................. 96
Digital Input Testing..................................................... 97
Keypad Test .................................................................. 97
Test Digital Output ....................................................... 97
Toggle Digital Output................................................... 98
Tuning and Control....................................................99
Introduction......................................................................... 99
Control Modes .................................................................... 99
On/Off Control.............................................................. 99
Proportional Control ..................................................... 100
Proportional and Integral Control ................................. 101
Proportional, Integral and Derivative Control .............. 101
Digital Output Control Forms....................................... 102
Setting Up and Tuning PID Loops ..................................... 104
Proportional Band (PB) Settings................................... 104
Integral Term (TI) Settings ........................................... 105
Derivative Term (TD) Settings ..................................... 105
General PID Constants........................................................ 106
Proportional Band Only (P) .......................................... 106
Proportional with Integral (PI)...................................... 106
PI with Derivative (PID)............................................... 106
Troubleshooting..........................................................109
Manual Controller Reset ............................................... 109
Returning your Unit to ANAFAZE .............................. 110
iv
MLS User’s Guide
Contents
Troubleshooting Stand-Alone Systems .............................. 110
MLS-PM Has No Power............................................... 110
Keys Don't Respond...................................................... 111
Controller Message: AIM Comm Failure ..................... 111
Checking Analog Inputs ............................................... 111
Checking PID Control Outputs..................................... 112
Checking Digital I/O..................................................... 112
Checking Computer Supervised Systems ........................... 113
Computer Problems ...................................................... 113
Serial Interface Problems.............................................. 113
Communications Problems ........................................... 114
Software Problems ........................................................ 115
Changing the EPROM .................................................. 116
Linear Scaling Examples ...........................................119
Example 1: Configuring a Pressure Sensor ........................ 119
Example 2: Configuring a Flow Sensor.............................. 120
Glossary ......................................................................121
v
Contents
vi
MLS User’s Guide
Overview
Overview
This manual describes how to install, setup, and operate a 16 or 32 MLS
controller. Included are seven chapters and a glossary of terms. Each
chapter covers a different aspect of your control system and may apply
to different users. The following describes the chapters and their
purpose.
• Introduction: Gives a general description of the MLS and its
related specifications.
• Installation: Describes how to install the MLS and its peripheral
devices.
• Using the MLS: Provides an overview of operator displays used for
system monitoring.
• Setup: Describes all the setup displays for the controller, and how to
access them.
• Tuning and Control: Explains PID control and provides tips for
tuning your system.
• Troubleshooting: Gives some basic guidelines for solving control
problems.
• Linear Scaling Examples: Provides an example configuring a pressure sensor, and one configuring a flow sensor.
MLS User’s Guide 1
Overview
System Diagram
The illustration below shows how the parts of the MLS are connected.
When unpacking your system, use the diagram and parts list below to
ensure all parts have been shipped. Please don't hesitate to call WatlowAnafaze's Technical Service Department if you have problems with
your shipment, or if the MLS' components are missing or damaged.
Parts List
• MLS Processor Module (PM)
• Controller Mounting Kit
• MLS AIM Module (16 or 32)
• AIM Cable, 4 foot.
• RS-232 or RS-485 Com Cable (optional)
• RTB Terminal Block
• 50-Pin Ribbon Cable
• Power Supply (optional)
2 MLS User’s Guide
Overview
Safety
Watlow-Anafaze has made efforts to ensure the reliability and safety of
the MLS™ Controller and to recommend safe usage practices in
systems applications. Please note that, in any application, failures can
occur. These failures may result in full control outputs or other outputs
which may cause damage to or unsafe conditions in the equipment or
process connected to the MLS Controller.
Good engineering practices, electrical codes, and insurance regulations
require that you use independent external safety devices to prevent
potentially dangerous or unsafe conditions. Assume that the WatlowAnafaze MLS Controller can fail with outputs full on, outputs full off,
or that other unexpected conditions can occur.
Install high or low temperature protection in systems where an
overtemperature or undertemperature fault condition could present a fire
hazard or other hazard. Failure to install temperature control protection
where a potential hazard exists could result in damage to equipment and
property, and injury to personnel.
The MLS includes a reset circuit that sets the control outputs off or to
the data stored in memory if the microprocessor resets--normally the
result of a power failure and power return. If a memory-based restart
will be unsafe for your process, program the MLS Controller to restart
with outputs off. For additional safety, program the computer or other
host device to automatically reload the desired operating constants or
process values on return of operating power. However, these safety
features do not eliminate the need for external, independent safety
devices in potentially dangerous or unsafe conditions.
Watlow-Anafaze also offers ANASOFT®, an optional software
program for IBM-AT® or IBM-PC® compatible computers. In the
event of a reset, ANASOFT will reload the MLS Controller with the
current values in computer memory. The user must ensure that this reset
will be safe for the process. Again, use of ANASOFT does not eliminate
the need for appropriate external, independent safety devices.
Contact Watlow-Anafaze immediately if you have any questions about
system safety or system operation.
MLS User’s Guide 3
Overview
4 MLS User’s Guide
Introduction
Introduction
The MLS is a modular control system with 32 fully independent loops
of PID control. It can function as a stand-alone controller; the MLS
processor module's 1/8 DIN front panel has a Liquid Crystal Display
(LCD) and touch keypad for local display and local parameter entry.
You can also use it as the key element in a computer-supervised data
acquisition and control system; the MLS can be locally or remotely
controlled via an RS-232 or RS-485 serial communications interface.
The MLS features include:
Direct Connection of Mixed Thermocouple Sensors: Versatile analog
inputs let you directly connect most thermocouples. Thermocouple
inputs feature reference junction compensation, linearization, PV offset
calibration to correct for sensor inaccuracies, T/C upscale break
detection, and your choice of Fahrenheit or Celsius display.
Resistive Temperature Detector Sensors are Standard Inputs: The
standard three-wire 100 W platinum DIN curve sensor is a standard
input for the MLS, as well as the Nickel RTD.
Automatic Scaling of Linear Analog Inputs: The MLS automatically
scales linear inputs used with other industrial process sensors. To scale
inputs, simply enter any two measurement points. For example, to scale
a pH sensor enter the endpoints: the low PV is 2.0 pH, while the high
PV is 14.0 pH. All subsequent values will be in pH.
Independently Selectable PID Output Modes: You can set each loop's
digital output to ON/OFF, Time Proportioning, Serial DAC, or
Distributed Zero Crossing mode. You can set each loop control mode
for ON/OFF, P, PI, or PID control with reverse or direct action output.
Flexible Alarm Outputs: You can set independent high/low process
alarms and a high/low deviation band alarm for each loop. Each alarm
can activate an individual digital output or it can be grouped with other
alarms to activate a single digital output.
Alarm or Control Outputs: You can set high/low deviation and high/
low process setpoints to operate separate digital outputs as on/off
control functions instead of as alarms. (The control function will not
have alarm notification or global alarm output.)
Global Alarm Output: When any alarm is triggered, the Global Alarm
Output is also triggered, and it stays on until you acknowledge it.
Watchdog Timer: The MLS watchdog timer (System Safe) output
provides a digital output which notifies you if the system fails.
MLS User’s Guide 5
Introduction
Front Panel or Computer Operation: You can set up and run the MLS
Controller from the processor module's front panel or from a local or
remote computer. Watlow-Anafaze offers ANASOFT, our IBM-AT or
IBM-PC compatible software you can use to operate the MLS.
ANASOFT has these features:
•Graphic Trend Plotting
•Process Overviews
•Printouts
•Data Archiving in Lotus-Compatible Files
Multiple Job Storage: You can store up to 8 jobs in protected memory
and access them by entering a single job number. Each job is a set of
operating conditions, including setpoints and alarms--so if a single oven
produces multiple products, simply enter one job number to set up every
loop.
Dual Outputs Standard for 16 Loops: The 16-loop MLS Controller
includes dual control outputs for each loop, and a second set of control
constants for heating and cooling applications.
Flexible Outputs Standard for 32 Loops: The 32-loop MLS
Controller is factory set for a single heat output for each input. Outputs
for loops 17-32 can be assigned as second outputs for loops 1-16.
6 MLS User’s Guide
Introduction
Specifications
This section shows specifications for the MLS, including inputs,
outputs, serial interface information, system power requirements, and
environmental and physical specifications.
Analog Inputs
Number of control loops
16 dual output or 32 single output plus one pulse
loop.
Number of analog inputs
16 (with AIM-16) or 32 (with AIM-32).
Input switching
Differential solid state MUX switching.
Input sampling rate
16 loops per second.
Analog over-voltage protection between
inputs
70 V peak to peak maximum.
Maximum analog input voltage
+10 V from + or - input to analog common.
Common mode voltage
500 Vac maximum analog common to MLS-PM
or MLS-AIM power supply common.
CMR (Common Mode Rejection)
>85 dB at 60 Hz, 110 dB typical.
A/D converter
Integrates voltage to frequency.
Integration time per loop
33.3 ms at 60 Hz line frequency.
Input range
-10 to +60 mV, or 0 to 25 V with scaling resistors.
Resolution
0.02%, greater than 12 bits (internal)
Accuracy
0.1% at 25°C
Calibration
Automatic zero and full scale.
Temperature coefficient
Less than 100 ppm/°C, 0.01% per °C.
Analog Ground to frame Ground Max.
potential
40 V
DC Common to frame Ground Max. potential
40 V
Thermocouple Ranges
J
-350 to 1400°F (-212 to 760°C)
K
-450 to 2500°F (-268 to 1371°C)
T
-450 to 750°F (-268 to 399°C)
B
150 to 3200°F (+66 to 1760°C)
S
0 to 3200°F (-18 to 1760°C)
R
0 to 3210°F (-18 to 1766°C)
MLS User’s Guide 7
Introduction
RTD Ranges
RTD1
-148.0 to 572°F (-100.0 to 300.0°C)
0.1°C
RTD2
-184 to 1544°F (-120 to 840°C)
1.0°C
RTD3
-94 to 572°F (-70 to 300°C)
1.0°C
Miscellaneous Specifications
T/C break detection
Pulse type for upscale break detection and
thermocouple alarm display.
Milliamp inputs
0-10 mA, 0-20 mA (4-20 mA), etc., with scaling resistors.
Infrared inputs
power supply included, with scaling resistors
for IRSM.
Source impedance
Measurements are within specification with
up to 500 ohms source resistance.
Analog Outputs
The Watlow-Anafaze Digital to Analog Converter (DAC) is an optional
module for MLS and CLS controllers. It lets you convert a distributed zero
crossing output signal to an analog process control signal. You can purchase
4-20 mAdc, 0-5 Vdc, and 0-10 Vdc versions of the DAC.
Watlow-Anafaze also offers the Serial DAC for precision open-loop control. 0-5 Vdc / 4-20 mAdc jumper selectable. Contact Watlow-Anafaze for
more information about the DAC and Serial DAC.
Digital Inputs
Number
8
Input voltage protection
Diodes to supply and common
Absolute maximum input
current
+10 mA
Voltage levels
<1.3V=Low; >3.7V=High
Maximum input current
1.2 mA from MLS with input at zero volts
Maximum switch resistance to pull input low
1 Kohm
Minimum switch off resistance
11 Kohm
8 MLS User’s Guide
Introduction
Digital Outputs
Standard Digital Outputs
Number
34 continuous 10 mA sink referenced to +5 Vdc of MLS
for SSR operation; 20 mA momentary peak sink.
User selectable outputs
34 PID control, Alarm/control, or Events. Two outputs are
not PID programmable.
Number of PID loops
16 or 32 programmable loops. 16-loop systems have dual
outputs. 32-loop systems have 32 single outputs, and you
can individually configure outputs 17-32 as a second outputs for loops 1-16.
PID control outputs
Time Proportioning, Distributed Zero Crossing, or On/
Off--all independently selectable for each loop.
Cycle Time
1-255 seconds.
Control Action
Reverse (heat) or Direct (cool), independently selectable
for each loop.
Off State Leakage Current
<.01 mA to DC common.
System Digital Outputs
Number of system digital
outputs
2
Configuration
1 global alarm, 5 Vdc at 10 mA sink; 1 System Safe (CPU Watchdog Timer), 5 Vdc at 10 mA sink.
MLS User’s Guide 9
Introduction
Miscellaneous Specifications
Serial Interface
Type
RS-232 3-wire or RS-485 4-wire.
Isolation
RS-232: None
RS-485: To EIA RS-485 specification.
Baud Rate
2400 or 9600, user selectable.
Error Check
BCC or CRC, user selectable.
Number of Controllers
1 with RS-232 communications, 32 with RS-485 communications,
16 with open frame units.
Protocol
Form of ANSI X3.28-1976, (D1, F1) compatible with Allen-Bradley PLC, full duplex.
System Power Requirements
MLS-PM supply input
10-28 Vdc at <1 amp
MLS-AIM supply input
4.75 to 5.25 Vdc at <0.5 amp, supplied by
MLS-PM
MLS-PS system power supply
Input: 120 Vac at 0.5 amp
Output: 12 Vdc at 1 amp
Environmental Specifications
Storage Temperature
-20 to 70ºC
Operating Temperature
0 to 50ºC
Humidity Conditions
10 to 95% non-condensing
Dimensions and Weight
MLS-PM
1.75 lbs., 1.89" x 3.78" x 6.75" (0.8 kg, 4.75 cm x 10 cm x 17
cm.)
MLS-AIM-TB
& AIM cards
1.50 lbs., 5.0" x 6.50" x 5.50" (0.7 kg, 12.5 cm x 16.25 cm x
13.75 cm.)
MLS-PS
1.50 lbs., 1.90" x 8.10" x 4.90" (0.7 kg, 4.75 cm x 20.25 cm x
12.25 cm.)
RTB
.5 lbs, 5.0’’ x 3.0’’ x 2.25’’ (.227 kg, 12.7 cm x 7.6 cm x 5.7 cm.)
10 MLS User’s Guide
Introduction
Expanded Parts List
The Expanded Parts List contains a technical description of each
component of your MLS Controller.
MLS Processor Module Technical Description
The MLS Processor Module (MLS-PM) is housed in an eighth-DIN
panel mount package. It contains the power supply circuits, the CPU,
RAM with a built-in lithium battery socket, EPROM, serial
communications, digital I/O, and the LCD screen and touch keypad.
Here's a side view of the MLS-PM:
• Screw terminals connect the power inputs and outputs.
• Input power is 10-28 Vdc at 1 amp.
• The +5 Vdc, 750 mAdc output power supply powers the MLS-AIM.
• A 50-pin flat ribbon cable connects the digital inputs and outputs to
the 50-pin terminal block (TB-50).
• The MLS uses 6-pin telephone-style connectors for internal and
external communications.
The firmware's operating intelligence resides in the plug-in EPROM, so
it's easy to update or change the MLS' firmware. The MLS stores its
operating parameters in battery-backed RAM, so if there's a power loss
the operating parameters are unchanged. The battery has a ten year shelf
life, and it is not used when the unit is on.
The CPU microprocessor performs all calculations for input signal
linearization, PID control, alarms, and communications.
The telephone connectors on the rear of the MLS-PM are used for:
• Communications to the MLS-AIM.
• RS-232 or RS-485 communications to an optional computer.
• For OEM customers, communications to the optional MLS Smart I/
O Module (MLS-SIOM).
The System safe output is Low (On) when the CPU is running; it keeps
a solid state relay closed. If the CPU stops working, the output goes
High (Off) and the SSR opens.
MLS User’s Guide 11
Introduction
The eight digital inputs are referenced to the MLS controller common;
an open input pulls them High (Off). When you short the input to
controller common the input goes Low (On). Do not connect external
power sources to the MLS' digital inputs.
Front Panel Description
The MLS-PM's panel mounted LCD screen and touch keypad provide
an intelligent way to operate the MLS. The on-board display driver
operates the liquid crystal display. The LCD has 16 alphanumeric or
graphic characters per line; it is backlit for viewing under low light
conditions. The 8-key keypad and on-board keyboard scanner allow you
to change the MLS' operating parameters, controller functions, and
displays.
The MLS' information-packed displays show process variables,
setpoints, and output levels for each loop. A bar graph display, single
loop display, scanning display and an alarm display offer a real-time
view of process conditions. Two access levels allow operator changes
and supervisor changes. The front panel looks like this:
MLS RTB Technical Description
Here's a picture of the RTB:
12 MLS User’s Guide
Introduction
The RTB is a screw terminal interface for control wiring which allows
you to easily connect external "real world" wiring to the MLS. The RTB
connects a 50-pin flat ribbon cable to a screw terminal block which
accepts #18 or #20 AWG wires. The ribbon cable receptacle has a
locking latch which keeps the cable in place.
The RTB's 34 digital outputs are sink outputs referenced to the +5 Vdc
power supply of the MLS Controller. They are Low when the output is
On. The firmware allows you to globally change the alarm and control
outputs' default state (no alarms) from On to Off for System Safe output.
The outputs are rated at a continuous 10 mAdc if all outputs are On at
the same time. Initial power up current should not exceed 20 mAdc.
MLS-AIM and AIM-TB Technical Description
The MLS Analog Input Module (MLS-AIM), containing the AIM-TB
(AIM Terminal Board) and AIM’s plug-in cards, receive input signals
from sensors and pass them to the MLS-PM.
The MLS-AIM-TB contains the power supply terminals, input signal
wiring screw terminals, input signal conditioning circuits, and terminal
connections for the AIM's plug-in cards. It also contains a cold junction
temperature sensor and room for the input scaling resistors, if required.
(RTDs, inputs greater than 60 mVdc, and mAdc current inputs require
input scaling resistors.) The AIM-TB has three slots for the plug-in
AIM cards.
There are two versions of the MLS-AIM: the AIM-16 and AIM-32. The
AIM-16 has one multiplexer (MUX) card, and the AIM-32 has two
MUX cards. These cards multiplex the 16 inputs each card receives.
Each -10 to 60 mVdc input is converted to a voltage that is transmitted
to the Voltage/Frequency (V/F) card. (The MUX cards also
automatically calibrate the zero and span of the analog amplifier and
measure the cold junction compensation temperature for thermocouple
(T/C) inputs.) Both the AIM-16 and AIM-32 have a V/F card, which
converts the input signal they receive from a voltage to a frequency. The
converted signal is then transmitted via the AIM COMM cable to the
MLS-PM for processing.
MLS User’s Guide 13
Introduction
Here's a picture of the MLS-AIM-32 and terminal block:
MLS Cabling Technical Description
Watlow-Anafaze provides all the cables required to install your MLS.
The 50 pin ribbon cable which connects the RTB to the MLS-PM is an
0.05 space conductor-zoned 50 pin cable. Pin #1 is at the red edge of the
cable.
The cables which connect the MLS-PM to the AIM-TB, the optional
Smart I/O Module (SIOM) and the computer are 6-conductor shielded
cable. (These cables are also known as RJ12 cable; they are available
from Newark Electronics and other suppliers.)
WARNING
These cables are not standard phone cables; standard cables are not shielded. Watlow-Anafaze pin
numbering convention is also reversed.
14 MLS User’s Guide
Installation
Installation
These installation instructions are written for nontechnical users. If you
are an electrician or you are technically proficient, they may seem
simple to you. Please at least skim all of the instructions, to make sure
you don't miss anything vital. (If you have installed a Modular Loop
System before, you may wish to use the Quick Start foldout to install
this system.)
This section explains installation for the MLS Controller only. If you are
installing another Watlow-Anafaze product (such as a Relay Interface
Board, IRSM, or an SDAC), see the manual shipped with it to learn how
to install it.
These symbols are used throughout this manual:
DANGER
This symbol warns you about a hazard to human
life.
WARNING
This symbol warns you of possible damage to
property or equipment.
NOTE
This symbol denotes information you must know
in order to proceed.
MLS User’s Guide 15
Installation
Read This Before Installation
WARNING
During installation and wiring, place temporary
covers over the housing slots and the rear of the
MLS so dirt and pieces of wire don't fall through
the slots. When you are finished with installation,
remove the covers.
Install the MLS so the airflow to the slots in the
housing is not restricted after installation. Make
sure that other equipment does not block airflow
to the housing slots.
Use #18 or #20 AWG wires and trim wire insulation to 1/4" (5 mm). Wire should fit inside the
terminal with no bare wire exposed, to prevent
contact between wires and the grounded case. Tin
any stranded wire.
Support power, input and output cables to reduce
strain on the terminals and to prevent wire
removal.
DANGER
Shut off power to your process before you install
the MLS. High voltage may be present even when
power is turned off! Reduce the danger of electric
shock after installation--mount the MLS in an
enclosure that prevents personal contact with electrical components.
The MLS measures input signals that are not normally referenced to ground, so the MLS inputs and
other signal lines can have high voltage present
even when power is turned off--for example, if you
inadvertently short a thermocouple to the AC
power line.
NOTE
Choose a panel location that leaves enough clearance to install and remove the MLS and its
components.
16 MLS User’s Guide
Installation
Recommended Tools
This section lists the tools you will need to install the MLS Controller.
Panel Hole Cutters
Use any of these tools to cut a hole in the panel:
• A jigsaw and metal file--for stainless steel and other heavyweight
panel doors.
• A Greenlee 1/8 DIN rectangular punch (Greenlee part #600-68)--for
most panel materials or thicknesses.
• A nibbler and metal file--for aluminum and other lightweight panel
doors.
Other Tools
You'll also need these tools:
• A Phillips head screwdriver.
• A flathead screwdriver for wiring.
• A multimeter.
• A phone connector crimping tool made of metal (optional).
Watlow-Anafaze provides all the cabling for the Modular Loop System.
If you have special cabling requirements and you make your own RJ12
cable, use a metal crimping tool for the connectors. (A metal tool makes
better connections than a plastic tool.)
Additional Hardware
The following additional hardware is also shipped to you:
• Four #6 screws for mounting the AIM-TB.
• #10 screws for mounting the optional MLS Power Supply.
MLS User’s Guide 17
Installation
Mounting the MLS-PM
This section tells you how to mount the MLS-PM.
NOTE
Mount the MLS-PM before you mount any other
component of the MLS. The processor module's
placement affects placement and wiring for the
MLS-AIM, MLS-PS, etc.
Mounting Environment
Install the MLS-PM in a location free from excessive (>50 ºC) heat,
dust, and unauthorized handling. The MLS-PM's 1/8 DIN package can
mount in panels up to 0.2" thick. Its dimensions are 1.89" x 3.78" x 6.1"
(48 x 96 x 156 mm), as shown below.
18 MLS User’s Guide
Installation
MLS-PM Mounting Steps
1. Use the template below to cut a hole in the panel. Be careful; the
0.02" (0.5 mm) tolerances don't allow much room for error. Use a
punch, nibbler, or jigsaw; file the edges of the hole.
WARNING
Make sure bits of wire and debris do not lodge in
the electronics, or else make sure you clean the
electronics before you connect power.
2. Insert the MLS-PM into the hole through the front of the panel.
3. Screw the top and bottom clips in place. If you expect much panel
vibration, use a rear support for the MLS and its interconnecting
cables.
MLS User’s Guide 19
Installation
Mounting the MLS-AIM
This section contains mounting instructions and diagrams for the MLSAIM.
NOTE
If you plan to install scaling resistors, mount them
on the AIM-TB before you mount the AIM-TB in
the panel. (If you mount the AIM-TB in the panel
before you mount the scaling resistors on it, you
will have to remove the AIM-TB from the panel to
install the scaling resistors.)
If you ordered an MLS-AIM-TB with scaling
inputs from Watlow-Anafaze, the scaling resistors
are already installed.
Mounting Environment
Install the MLS-AIM in a location free from excessive (>50ºC) heat,
dust, and unauthorized handling.
The MLS-AIM measures 6.5" x 5" x 7" (165 x 127 x 178 mm). Leave 6"
of clearance above the MLS-AIM, so you can remove the entire unit (or
just the AIM cards) if necessary.
The figure on the next page shows an overhead view of the AIM-TB and
MUX cards, with dimensions, scaling resistor locations and hole
locations. It also shows the AIM communications port and the insertion
of the MUX cards in the AIM Terminal Block.
20 MLS User’s Guide
Installation
Scaling Resisters
AIM Communications Port (Tel. 1)
Mounting Holes
Mounting Steps
1. Choose an appropriate place to install the MLS-AIM.
2. Place the MLS-AIM where you will mount it and use a pencil to trace
around the plastic standoffs on the AIM. (If you wish, you can use the
AIM mounting template in the Quick Start foldout to position the
holes.)
3. Drill four #6 or #8 holes in the chosen location. (#8 holes provide
more clearance.)
4. Place the MLS-AIM where you will mount it. Insert the #6 screws in
the plastic standoffs and tighten them. You may use self-tapping
screws instead, but be sure to remove any loose metal filings after
you are finished mounting the MLS-AIM. Use 3/4" screws with
internal star lock washers to ensure a good Frame Ground connaction.
MLS User’s Guide 21
Installation
Mounting the RTB
To mount the RTB, slide it onto a DIN rail. Watlow-Anafaze
recommends Phoenix Contact’s NS32 perforated DIN rail (part number
12-01-00-2). Mount the DIN rail according to Phoenix Contact’s
instructions and slide the RTB onto it.
WARNING
Do not connect power to the MLS now. Test the
unit first, as explained in the Power Wiring and
Controller Test section.
22 MLS User’s Guide
Installation
Mounting the MLS-PS
Follow these instructions to mount the MLS-PS.
If you use your own power supply for the MLS, please refer to the
power supply manufacturer's instructions for mounting information.
Choose a power supply that supplies a regulated 7-28 Vdc at 1 watt, and
isolated return line.
Mounting Environment
The MLS-PS measures 1.75" x 8" x 5". Leave enough clearance around
the power supply that you can remove it later.
Mounting Steps
The MLS-PS has a bracket at each end of the unit. Each bracket has
three screw holes which will accept #6 or #10 screws. To mount the
MLS-PS, insert screws into the brackets and tighten them.
MLS User’s Guide 23
Installation
Wiring Your System
This section explains how to wire the components of your system.
Below is the system connections diagram reprinted here for your
convenience. (See the next page for wiring instructions.)
24 MLS User’s Guide
Installation
Wiring Recommendations
This section gives general wiring recommendations.
DANGER
Never wire bundles of low power Watlow-Anafaze
circuits next to bundles of high power AC wiring.
Instead, physically separate high power circuits
from the controller. If possible, install high voltage
AC power circuits in a separate panel.
• Use stranded wire. (Use solid wire for fixed service; it makes intermittent connections when you move it for maintenance.)
• Use #18 or #20 AWG wire. Larger or smaller sizes may be difficult
to install, may break easily, or may cause intermittent connections.
• Use shielded wire. (The electrical shield protects the MLS from
electrical noise.) Connect one end of the input wiring shield to the
MLS panel's 120 Vac panel ground, and connect one end of the output wiring shield to the MLS panel's 120 Vac panel ground. (If
your system requires a different shield configuration, contact Watlow-Anafaze for more information.)
For more information about noise suppression, see Noise Suppression.
MLS User’s Guide 25
Installation
Cable Recommendations
Use these cables or their equivalent.
Function
MFR P/N
No. of Wires
AWG
Analog Inputs
Belden #9154
Belden #8451
2
2
20
22
RTD Inputs
Belden #8772
Belden #9770
3
3
20
22
T/C Inputs
T/C Ext. Wire
2
20
Carbon Probe Input
Belden #88760
2
18
Digital PID Outputs and Digital
I/O
Belden #9539
Belden #9542
Ribbon Cable
9
20
50
24
24
Analog Outputs
Belden #9154
Belden #8451
2
2
20
22
Computer Communication:
RS232, RS422, RS485, or 20
ma
Belden #9729
Belden #9730
Belden #9842
Belden #9843
4
6
4
6
24
24
24
24
Noise Suppression
If the MLS outputs control dry-contact EM relays with inductive loads-like alarm horns and motor starters--you may get Radio-Frequency
Interference (RFI, or "noise") This section explains how to avoid noise
problems; read it before you wire the MLS.
Symptoms of RFI
• The MLS display blanks out and then reenergizes, as if power had
been turned off for a moment.
• The process value does not display correctly.
• The MLS CPU may reset; if it does, it loses its' PID output levels.
RFI may also damage the digital output circuit--so digital outputs will
not energize. If the digital output circuit is damaged, return the
controller to Watlow-Anafaze for repair.
Avoiding RFI
Where possible, use solid state relays (SSRs) instead of electricalmechanical (EM) relays. If you must use EM relays, try to avoid
mounting them in the same panel as Watlow-Anafaze equipment.
Separate the 120 Vac power leads from the low level input and output
leads connected to the MLS. Don't run the digital output or PID control
output leads in bundles with 120 Vac wires. (Never run input leads in
bundles with high power leads--see the General Wiring section.)
26 MLS User’s Guide
Installation
If you must use EM relays and you must place them in a panel with
Watlow-Anafaze equipment, use a .01 microfarad capacitor rated at
1000 Vac (or higher) in series with a 47 ohm, ½ watt resistor across the
normally open (NO) contacts of the relay load. This network is known
as an arc suppressor or snubber network.
You can use other voltage suppression devices, but they are not usually
required. For instance, you can place a metal oxide varistor (MOV)
rated at 130 Vac for 120 Vac control circuits across the load, which
limits the peak AC voltage to about 180 Vac. You can also place a
transorb (back to back zener diodes) across the digital output, which
limits the digital output loop to 5 Vdc. (You can get these parts from
Watlow-Anafaze.)
The above steps will eliminate most noise problems. If you have further
problems or questions, please contact Watlow-Anafaze.
Wiring and Testing Your System
After you install each component of the MLS, use this section to
connect them. If these instructions are not clear to you, refer to the
system connections diagram for more information. (These instructions
are written for non-electricians. If you are an experienced electrician,
they may seem elementary to you. If so, feel free to skim them.)
When you have connected each component of your system, install and
connect input and output devices. For help with inputs and outputs, see
the Outputs and the Inputs sections in this chapter.
Connecting Power and RTB to MLS-PM
1. Remove the temporary covers you placed on the MLS' housing.
2. Connect the power supply terminal labeled "DC COM" to the terminal labeled "GND" on the Processor Module. This terminal is DC
common; it is not frame, chassis or earth ground.
3. Connect the power supply terminal labeled "+12V" to the terminal
labeled "+V" on the Processor Module.
4. Connect the 50-pin ribbon cable to the Processor Module. Plug it in
so that the red stripe is on the left side, under TB1.
5. Connect the ribbon cable to the RTB. Plug it in so that the red stripe is
closest to screw terminal 1.
Connecting Power and Common to AIM-TB
1. Connect the terminal labeled "EX" on TB1 of the MLS-PM to the terminal labeled "+5V" on the MLS-AIM.
2. Connect the terminal labeled "COM" on TB1 of the MLS-PM to the
MLS-AIM terminal labeled "DC COMMON".
MLS User’s Guide 27
Installation
3. Plug the AIM communications cable into the slot on the MLS-PM
labeled "To AIM".
4. Plug the other end of the AIM communications cable into the slot on
the MLS-AIM labeled "Tel 1". (The slot is on top of the V/F card.)
WARNING
Do not turn on the AC power now. Test the connections first, as explained below.
5. Connect AC power wires to the MLS-PS.
6. Connect "
" terminal on MLS AIM to frame Ground.
Testing Connections
WARNING
Reversed polarity or incorrect voltage to the PM
or AIM will damage your MLS, and you will need
to return it to Watlow-Anafaze for repair. Please
don't damage your unit! Read this section completely and follow the steps below before you apply
power to your MLS.
1. Unplug TB1 (the green block which contains the Ex, GND, and +V
terminals) from the MLS-PM.
2. Unplug the AIM cards from the AIM-TB:
• Carefully insert a screwdriver in the hole on the side of the AIM's
metal jacket.
• Gently press the screwdriver blade against the metal standoffs which
separate the AIM cards.
• Continue pressing gently until the AIM cards pop loose from the
plastic bracket that holds them in place. Then, carefully grasp the
AIM cards by the edges and remove them from the metal bracket.
You have removed the parts of the MLS which will be
damaged by excess voltage, so turn on the AC power
and use a voltmeter to check voltages:
3. Touch the meter Common lead to the "COM" terminal on the MLSPM (the green block with the wires). The voltage on the "+V" terminal of the MLS-PM should be +10 to 28 Vdc. The voltage on the
"EX" terminal of the MLS-PM should read 0 Vdc.
4. If the voltages are within the limits described above:
• Turn off the power.
• Plug TB1 (the green block which contains the screw terminals) back
into the MLS-PM.
28 MLS User’s Guide
Installation
• Turn the power back on. The Processor Module's display should light
up, and after about a second the Bar Graph display should appear,
followed by the message "AIM COMM FAIL".
5. Connect the Common lead of the voltmeter to TB3 and the power
lead of the voltmeter to the AIM-TB terminal labeled "+5V". The
voltage on the "+5V" terminal should be between +4.75 and +5.25
Vdc.
6. If the voltages are within the limits described above:
A. Turn off the power.
B. Carefully insert the AIM cards back into the AIM Terminal
Block.
C. If you have unplugged the AIM COMM. cable, plug it back in.
D. Press and hold the No key. While pressing it, turn the power
back on. (This procedure is known as a manual controller reset
or No Key reset.)
The green LEDs on the AIM should blink, which means that the
unit is working normally. If they do not blink, contact WatlowAnafaze.
E. The MLS-PM will display a "T/C Break" alarm message for
each channel. These messages are normal; to clear them, press
Alarm Ack once for each control loop.
MLS User’s Guide 29
Installation
Testing Your System
This section explains how to test the controller after installation.
MLS-AIM Test
Use this procedure to test the MLS-AIM before you connect inputs to it.
1. Connect a wire from the A+ terminal for loop 1 to the A- terminal for
loop 1.
2. Turn on power to the MLS-PM.
3. Press the ALARM ACK key to clear the alarm messages displayed
on the MLS-PM's screen.
4. Press the YES key to reach the single loop display for Loop 1. The
MLS-AIM-TB contains an ambient temperature sensor, so Loop 1
should display room temperature. If it does not, contact WatlowAnafaze.
RTB Test
1. Turn on power to the MLS.
2. Measure the +5Vdc supply at the RTB:
A. Connect the voltmeter's Common lead to RTB terminal #3.
B. Connect the voltmeter's Power lead to RTB screw terminal #1.
The voltage should be 4.75 to 5.25 Vdc.
C. Connect the Power lead to RTB screw terminal #2. The voltage
should be 4.75 to 5.25 Vdc.
D. Connect the Power lead to RTB screw terminal #4. The voltage
should read 0 volts.
PID Output Test
1. Connect the voltmeter power lead to RTB screw terminal #1.
2. Connect the Common lead to the PID output pin.
3. If you have not connected a load to the output, connect a 500 ohm to
100 Kohm resistor between RTB screw terminal 1 and the PID output
pin.
4. Use the digital output test (in the Manual I/O Test menus) to turn the
digital output on and off. When the output is off, the output voltage
should be less than 1V. When the output is on, the output voltage
should be between 3.75 and 5.5V.
30 MLS User’s Guide
Installation
NOTE
Your MLS is shipped with heat outputs enabled
and cool outputs disabled. You can disable any PID
output and use it for other digital output functions.
All digital outputs and PID outputs are sink outputs referenced to the 5Vdc supply. These outputs
are Low when they are On.
All digital inputs are Transistor-Transistor Logic
(TTL) level inputs referenced to control common.
Outputs
This section discusses the MLS' PID control and alarm outputs.
WARNING
Control outputs are connected to the MLS's logic
ground when the control output is On (Low). Be
careful when you connect external devices that
may have a low side at voltage other than controller ground, since you may create ground loops.
If you expect grounding problems, use isolated
solid state relays and isolate the control device
inputs.
The MLS provides dual PID control outputs for each loop. These
outputs are on the 50 pin ribbon cable connector which connects to the
RTB. You can enable or disable them.
• The default setting is heat outputs enabled, cool outputs disabled.
• You can program each output for on/off, TP, or DZC control.
• You can program each output for direct or reverse action.
• You can program a deadband for heat/cool; within that deadband
both outputs will be Off.
Output Wiring Recommendations
When you wire output devices to the RTB, use multicolored stranded
shielded cable for analog outputs and PID digital outputs connected to
panel mount SSRs.
• Analog outputs usually use a twisted pair.
• Digital outputs have 9 to 20 conductors, depending on wiring technique.
MLS User’s Guide 31
Installation
Ribbon Cable Recommendations
Use the 50-pin connector for both ends of the 50 pin flat ribbon cable.
(Do not connect either end to a screw terminal; the cable wire is too
small to withstand much flexing.)
Do not exceed 15' of 50-conductor cable.
Using the Cable Tie Wraps
When you have wired outputs to the TB-50, install the cable tie wraps
shipped with it. This diagram shows the cable tie wrap holes.
Each row of terminals has a cable tie wrap hole at one end. Thread the
cable tie wrap through the cable tie wrap hole. Then wrap the cable tie
wrap around the wires attached to that terminal block.
32 MLS User’s Guide
Installation
PID Control and Alarm Output Connections
Typical digital control outputs use external optically-isolated solid-state
relays (SSRs). The SSRs use a 3 to 32 Vdc input for control, and you
can size them to switch up to 100 amps at 480 Vac. For larger currents,
use these optically-isolated relays to drive contactors.
NOTE
Control outputs are sink outputs. They are Low
when the output is On. Connect them to the negative side of Solid State Relays.
The next figure shows sample heat/cool and alarm output connections.
System Safe (Watchdog Timer) constantly monitors the MLS CPU. It is
a SINK output located on RTB terminal #6. (Do not exceed the 10
mAdc rating for the System Safe output.) Its output is Low (on) when
the CPU is operating; when it stops operating, the output goes High
(off), de-energizing the SSR.
Here's the recommended circuit for the System Safe output:
+5 Vdc
(RTB pin 2)
+
SSR
System safe
(RTB pin 6)
_
MLS User’s Guide 33
Installation
RTB Connections
Connect outputs to the RTB as shown in the table below.
Terminal
Function
PID Output
Terminal
Function
PID Output
1
+5 Vdc
2
+5 Vdc
3
CTRL COM
4
CTRL COM
5
Spare
6
System Safe
7
Pulse input
8
Global Alarm
9
DIG Output 1
Heat 1
10
DIG Output 34*
11
DIG Output 2
Heat 2
12
DIG Output 33
Pulse Loop Heat
13
DIG Output 3
Heat 3
14
DIG Output 32
Heat 32/Cool 16
15
DIG Output 4
Heat 4
16
DIG Output 31
Heat 31/Cool 15
17
DIG Output 5
Heat 5
18
DIG Output 30
Heat 30/Cool 14
19
DIG Output 6
Heat 6
20
DIG Output 29
Heat 29/Cool 13
21
DIG Output 7
Heat 7
22
DIG Output 28
Heat 28/Cool 12
23
DIG Output 8
Heat 8
24
DIG Output 27
Heat 27/Cool 11
25
DIG Output 9
Heat 9
26
DIG Output 26
Heat 26/Cool 10
27
DIG Output 10
Heat 10
28
DIG Output 25
Heat 25/Cool 9
29
DIG Output 11
Heat 11
30
DIG Output 24
Heat 24/Cool 8
31
DIG Output 12
Heat 12
32
DIG Output 23
Heat 23/Cool 7
33
DIG Output 13
Heat 13
34
DIG Output 22
Heat 22/Cool 6
35
DIG Output 14
Heat 14
36
DIG Output 21
Heat 21/Cool 5
37
DIG Output 15
Heat 15
38
DIG Output 20
Heat 20/Cool 4
39
DIG Output 16
Heat 16
40
DIG Output 19
Heat 19/Cool 3
41
DIG Output 17
Heat 17/Cool 1
42
DIG Output 18
Heat 18/Cool 2
43
DIG Input 1
44
DIG Input 2
45
DIG Input 3
46
DIG Input 4
47
DIG Input 5
48
DIG Input 6
49
DIG Input 7
50
DIG Input 8
* If you install an Watlow-Anafaze Serial Digital to Analog Converter (SDAC), the MLS uses digital output #34
for a clock line. You cannot use output #34 for anything else when an SDAC is installed.
34 MLS User’s Guide
Installation
AIM Communications Failure
The controller continuously checks communications between the MLSPM and the AIM. If communication stops for more than five seconds,
the MLS-PM display indicates AIM COMM FAIL, the PID mode
changes to manual, and the controller sets every output to the output
override percentage.
WARNING
PID outputs remain in manual mode after an AIM
communications failure. After an AIM failure,
change the PID control status back to automatic
mode for each control loop.
An AIM communications failure also activates the global alarm output.
If you have selected a digital output from the Global Parameters menu,
an AIM communications failure also activates the output.
MLS User’s Guide 35
Installation
Inputs
This figure shows the AIM cards (also known as the MUX cards) and
AIM-TB, with scaling resistor locations.
Scaling Resisters
AIM Communications Port (Tel. 1)
• The loop input number is marked on the terminal block: the number
1 indicates an input for loop 1, the number 2 an input for loop 2, etc.
• The A+ terminal is the positive input of the analog signal.
• The A- terminal is the negative input of the analog signal.
36 MLS User’s Guide
Installation
• The A COM (AUX) terminal is the Auxiliary input. This is analog
common used for RTD inputs.
WARNING
Do not exceed 10 Vdc between loops. Excess voltage may damage the Analog Input Module (AIM).
Input Wiring Recommendations
Use multicolored stranded shielded cable for analog inputs. WatlowAnafaze recommends that you use #20 AWG wire. (If the sensor
manufacturer requires it, you can also use #22 or #24 AWG wiring.)
Most inputs use a shielded twisted pair; some require a 3-wire input.
Input Scaling
You can connect thermocouples, 4-20 mA current inputs, voltage inputs,
and 2- or 3- wire RTD inputs to the MLS. If you need to scale input
voltages or convert milliamp inputs to match the -10 to 60 mV (-16.7%
to 100%) input range, install scaling resistors. Watlow-Anafaze can
supply factory-installed input scaling resistors--order option MLS-SIXX (See the next table for standard scaling resistor values), or special
input kits MLS-SIK-XX (call Watlow-Anafaze for XX number).
Scaling Values
• Scaling values for mVdc ranges are standard metal film values with
+0.25% accuracy if 0.1% tolerance resistors are used.
• Scaling values for mAdc ranges are 0.1% tolerance with +0.10%
accuracy.
• Scaling values for RTD ranges are 0.05% tolerance. Use these values
to remain within factory specifications for the RTD inputs.
• Use 0.1% metal film, 1/4 watt resistors. Higher tolerances may cause
significant errors. Use the MLS' built-in linear scaling to correct
any errors due to resistor tolerance. You can also install other components (like capacitors) for signal conditioning; please consult
Watlow-Anafaze for more information.
This figure shows an input circuit. RA, RB, RC, and RD refer to the
scaling resistor locations printed on the MLS-AIM's terminal board.
MLS User’s Guide 37
Installation
To
MLS-AIM
Circuitry
Analog
Input
Terminal
A+
IN +
Internal
+2.5 Vdc
Reference
RA
RD
RB
RC
A-
IN C .47 uF
A COM
C .47 uF
This table shows scaling resistor values.
Input Range
RA
RB
All T/C, 0-60 mVdc
RC
RD
Jumper
RTD1 -100.0 to 300.0ºC
RTD2, -120 to 840ºC
RTD3, -70 to 300ºC
5.49K
11.0K
11.0K
0-10 mAdc
0-20 mAdc (4-20 mA)
-450 to
2500
0-100 mVdc
0-500 mVdc
0-1 Vdc
0-5 Vdc
0-10 Vdc
0-12 Vdc
5.49K
11.0K
11.0K
80
100
100
Jumper
Jumper
6.0
3.0
499
5.49K
6.91K
39.2K
49.9K
84.5K
750
750
422
475
301
422
Input Calibration
The MLS provides offset calibration for T/C, RTD, and other fixed
ranges. It also provides offset and span (gain) calibration for linear and
pulse inputs. (Offset and span calibration convert linear analog inputs
into engineering units using the Mx+B function.) The offset range is 300 to +300 units; the magnitude of the offset depends on the input type
and span you select.
Follow these steps to use the MLS' offset and span calibration:
1. Install scaling resistors that will provide an appropriate full scale voltage. (If you have any doubts about your ability to install scaling resistors, contact Watlow-Anafaze.)
38 MLS User’s Guide
Installation
2. Select the # of digits and decimal point location for the full scale PV
display. The smallest possible range is -0.9999 to +3.0000; the largest
possible range is -9999 to 30000.
3. Enter the zero and full scale values (process variables) you want displayed when the input signal is at zero and full scale.
T/C Inputs
WARNING
Use ungrounded thermocouples (thermocouples
which have the T/C junction isolated from the
metal protection sheath). Grounded thermocouples will damage the MLS if voltage between the
loops exceeds 10 volts.
If you are installing the MLS in an existing temperature control system, check all grounded T/C
assemblies in the system. Make sure there is no
voltage between T/C leads.
You can connect all T/C types directly to the MLS. Watlow-Anafaze
provides J, K, T, R, S, and B type linearization and cold junction
compensation. (Other thermocouple types require custom input ranges;
contact Watlow-Anafaze for more information about them.)
Wiring Recommendations
Follow these recommendations for thermocouple wiring:
• Use 18 or 20 AWG thermocouple (T/C) extension wire for all thermocouple inputs.
• Most T/C wire is solid unshielded wire. Use shielded wire if required
at your installation; ground one end only.
• Use less than 500' of T/C extension wire. Longer wire runs exceed
accuracy and source impedance specifications.
• Install T/C wiring in a separate conduit away from AC power (the
120 Vac supply) and high power (240 Vac or higher) wiring.
MLS User’s Guide 39
Installation
Connecting Thermocouples
Connect the positive T/C lead to the A+ terminal. Connect the negative
T/C lead to the A- terminal of TB1. The figure below shows a typical
thermocouple connection.
• Use 20 gauge T/C extension wire for all T/C inputs.
• If you use shielded wire, tie the shield to panel ground.
• Install a jumper or zero ohm resistor in location RC on the AIM-TB
if it had been removed.
This figure shows a typical thermocouple connection.
White
Type J T/C
IN +
Red
IN –
Shield
RTD Inputs
The standard industrial RTD is an 100 ohm, three-wire, platinum
assembly as shown in the next figure. Watlow-Anafaze highly
recommends that you use the three-wire RTD to prevent reading errors
due to cable resistance.
• If you order an RTD1, RTD2, or RTD3 configuration, we will configure your MLS for the standard three-wire RTD.
• If you must use a two-wire RTD, jumper A- to AUX.
• If you must use a four-wire RTD, do not connect the fourth wire.
Watlow-Anafaze offers three standard DIN 385 curve RTD input
ranges, as shown in the table below:
RTD
Type
Input Range
Display
Resolution
RTD1
-100.0 to 300.0 C
-148.0 to 572.0 F
0.1 C
0.1 F
RTD2
-120 to 840 C
-184 to 1544 F
1C
1F
RTD3
-70 to 300 C
-94 to 572 F
1C
1F
This figure shows a typical 3-wire RTD connection.
40 MLS User’s Guide
Installation
Rear Terminal Block
Connections
Black
IN +
Black
IN –
100 Ohm RTD
Red
Analog Common
Current Inputs
To install current (milliamp) inputs, place resistors in the input section
which convert the milliamp input into a voltage. (You can get different
current input ranges if you select different resistor values.) The input
connections for these inputs are the same as the input connections for
voltage inputs.
Voltage Inputs
Connect the + side of the voltage input to the A+ terminal. Connect the side of the input to the A- terminal. The voltage input range is -10 to 60
mV. Scale signals larger than 60 mV with a scaling resistor which makes
full scale input 60 mV.
The next figure shows two resistors. RA and RB are not loaded. RC is
the voltage reducing or current limiting resistor, and RD is the 60 mV
full scale dropping resistor. RD is normally less than 500 ohms, and it
should never exceed 1000 ohms.
To
Circuitry
IN +
RD
IN –
RC
Unused Inputs
Set the input type for unused inputs to "SKIP" to avoid the default T/C
break alarms.
MLS User’s Guide 41
Installation
Communications
The MLS is factory-configured for either RS-232 or RS-485
communications. When you order your unit, specify the type of
communications you need.
• If you use one MLS and you connect it to a computer less than 50
feet away, you can use RS-232 communications.
• If you use more than one computer, or if the computer and controller
are more than 50 feet apart, use RS-485 communications.
PC-compatible computers typically use RS-232 communications. If the
MLS is configured for RS-232 communications, you can connect it
directly to the serial communications connector on an IBM-PC or
compatible computer.
If you use RS-485 communications, attach an optically isolated RS-232/
RS-485 converter to the computer. You can use an internal converter
card or an external plug-in converter.
Changing Communications
Follow these instructions to change the unit's communications between
RS-485 and RS-232:
1. Unplug any cables connected to the MLS-PM.
2. If you already installed the MLS-PM in a panel, remove it from the
panel.
3. Unscrew the screws on the PM's casing. (There are either two or four
screws on the sides of the casing. There are two additional screws on
the top of the casing.)
4. Move jumpers JU2, JU4, and JU14 on the upper PC board.
5. If you are changing communications for the last unit on the serial
communications line, also move jumper JU3. Installing this jumper
places a 200 ohm impedance on the line.
6. Reverse instructions 1-3 to reinstall the unit.
Connecting RS-232 Communications
The RS-232 interface is a standard phone cable with a 6-pin male phone
connector on one end and a 9- or 25-pin D-sub female connector on the
computer end. (You can order this cable--called an MLS COM cable-from Watlow-Anafaze. If you order it, specify the length of cable and
the type of D-sub miniature connector you need.)
42 MLS User’s Guide
Installation
1. Plug the phone connector into the slot labeled "RS-232/RS-485" on
the rear of the MLS-PM.
2. Plug the D-sub connector into the communications connector.
This table shows RS-232 connections for 25-pin and 9-pin connectors.
Computer Connector
DB 25
DB 9
MLS RS-232 Pin
Number
RX Pin 3
RX Pin 2
TX Pin 5 Yellow
TX Pin 2
TX Pin 3
RX Pin 1 Blue
GND Pin 7
GND Pin 5
GND Pin 4 Green
NOTE
The pin numbers and colors are not industry standard. Watlow-Anafaze numbers the pins from
right to left with 1 on the right as you’re looking at
the back of the MLS-PM. Colors vary depending
on the manufacturer. The figure below shows a
back of an MLS-PM.
6 1
Connecting RS-485 Communications
RS-485 specification is for "balanced line" operation; it is not true
differential, so you must supply a common ground connection. Use a
fifth wire (which should not be shield, if possible) or a common ground
connection to establish the common ground.
Do not use the common ground connection unless the common mode
voltage between stations at your installation exceeds the RS-485
specification of 7 volts peak; in that case, use a fifth wire.
The following diagram shows the recommended system hookup. The
transmitter from the host computer connects in parallel to the controller
receivers, and the host computer receiver connects in parallel to the
controller transmitters. Watlow-Anafaze recommends that you use a
single "daisy chain" rather than "octopus connections" or "spurs". In
addition, use a terminating resistor (a 200 ohm resistor laid across the
line at the furthest point from the transmitter) at each end of the
transmission line.
This figure shows the MLS RS-485 connections.
MLS User’s Guide 43
Installation
Black Box
LD 485A
TXA
TXB
RXA
RXB
Ground
MLS T3A/B
[n] RJ12
MLS T3A/B
[1] RJ12
Red
Blue/White
Black
Yellow
Silver
RX+ #3
RX- #1
TX+ #2
TX- #5
#6
Red
Blue/White
Black
Yellow
Silver
RX+ #3
200Ω
RX- #1
TX+ #2
TX- #5
#6
NOTE
Connect the shields to earth ground only at the
computer or other 485 interface. Do not connect
the shield at the MLS. Connect a 200 ohm terminating resistor between RX- and RX+ at the last
MLS (Ju3).
The loop resistance of the transmission line (wire
only, not terminating resistor) must not exceed 200
ohms.
This table shows RS-485 connections.
Line
RS-485 Connection
Color
TXB
RX+Pin 1
Blue/White
TXA
RX-Pin 3
Red
RXB
TX+Pin 5
Yellow
RXA
TX-Pin 2
Black
Ground Pin 4
Green
Shield
Shield Pin 6
(Not jumpered internally)
EIA Standard RS-485 specifies the electrical characteristics of
transmitters and receivers for digital multi-point systems. WatlowAnafaze equipment meets RS-485 and RS-422 standards. However, RS485 does not specify transmission lines, signaling rates, protocols, etc.
Watlow-Anafaze recommends the following:
• Maximum signaling rate: 9600 baud.
• Twisted shielded pairs for the RS-485 cables.
44 MLS User’s Guide
Installation
Recommended Wire Gauges
This table shows maximum distances and wire gauges for
communications wiring:
Distance
Wire Gauge
Recommended Cable
4000 ft.
24 AWG
Belden #9729
Belden #9842
6000 ft.
22 AWG
Belden #9184
You may wish to use a shield, depending on your noise environment and
grounding problems. These cables are shielded.
MLS User’s Guide 45
Installation
46 MLS User’s Guide
Using the MLS
Using the MLS
This chapter explains how to use the front panel to operate the
controller. (If you are using ANASOFT, see the operation instructions in
the ANASOFT User's Guide.) The next figure shows a map of the
operator menus and displays accessible from the MLS Controller's front
panel. You don't need to enter a passkey sequence to reach these menus.
To make detailed changes to global parameters, loop inputs, control
parameters, outputs, and alarms via the setup menus, you must enter a
special sequence of keys. (For more information about the Setup menus,
see Chapter 4: Setup.)
MLS User’s Guide 47
Using the MLS
Front Panel
The MLS front panel provides a convenient interface with the
controller. You can use the front panel keys to program and operate the
MLS, or you can use ANASOFT, a program designed specifically for
ANAFAZE controllers. (See the ANASOFT User's Guide for more
information about ANASOFT, or contact ANAFAZE.)
This figure shows the MLS' front panel.
Ramp/Soak
Not available
at this time
Alarm Ack
Acknowledges
Man/Auto
Changes loop output
control from Automatic
to Manual or Tune
Assigns output power
level of manual loops
Change Setpoint
Changes process
Setpoint
Enter
yes
Back
Selects a menu
Answers Yes
to Yes/No prompts
Increases a number
or choice
Aborts editing
and returns
to a previous
menu
No
Skips a menu
Answers No to Yes/No
prompts
Decreases a number or
choice you are editing
48 MLS User’s Guide
Stores data or menu
choices & advances to
the next menu
Starts scanning mode
(if pressed twice)
Using the MLS
Front Panel Keys
Yes (Up)
Press Yes to do these things:
• Select a menu.
• Answer Yes to Yes/No prompts.
• Increase a number or choice you're editing.
• Stop scanning mode.
No (Down)
Press No to do these things:
• Skip a menu when the prompt is blinking.
• Answer No to Yes/No prompts.
• Decrease a number or choice when editing.
• Stop scanning mode.
• Perform a manual controller (No Key) reset (see next page).
WARNING
A manual controller (No Key) reset clears the controller's RAM and reinitializes the MLS-PM's
factory default values.
A manual controller reset is appropriate in these situations:
• After you change the PROM.
• In some cases when troubleshooting (see Chapter 6: Troubleshooting).
Back
The Back key works like an "escape" key. Press it to:
• Abort editing.
• Return to a previous menu.
• Stop scanning mode.
MLS User’s Guide 49
Using the MLS
• Switch between Bar Graph and Single Loop display.
Enter
Press the "Enter" key to:
• Store data or a menu choice after editing.
• Go on to the next menu.
• Start scanning mode (if pressed twice).
Chng SP
• Press this key to change the loop setpoint.
Man/Auto
Press the Man/Auto key to:
• Toggle a loop between manual and automatic control.
• Adjust the output power level of manual loops.
• Automatically tune the loop.
Ramp/Soak
Ramp/Soak isn't available for the standard MLS. When pressing this
key, a message appears: OPTION UNAVAILABLE.
Alarm Ack
Press Alarm Ack to:
• Acknowledge an alarm condition.
• Reset the global alarm digital output.
50 MLS User’s Guide
Using the MLS
Displays
This section describes the MLS' displays.
Viewing Several Loops: Bar Graph Display
When you connect power to the MLS, it displays general symbolic
information for loops 1-8. This display is called Bar Graph mode. The
next figure shows a picture of the Bar Graph display.
LOOP
PROCESS
01
AAAA
UNITS
08
MAMA
ALARM SETPOINT
STATUS
OUT%
This table explains the symbols on the top line of the Bar Graph display.
Symbol
Symbol’s Meaning
<
Loop is in low process or low deviation alarm.
>
Loop is in high process or high deviation alarm.
Loop is above setpoint. If you enable the high or low deviation alarm, this symbol is scaled to it. If you don’t enable
these alarms, these symbols are scaled to the setpoint +5% of
the sensor’s range.
Loop is at setpoint. If you enable the high or low deviation
alarm, this symbol is scaled to it. If you don’t enable these
alarms, these symbols are scaled to the setpoint +5% of the
sensor’s range.
Loop is below setpoint. If you enable the high or low deviation alarm, this symbol is scaled to it. If you don’t enable
these alarms, these symbols are scaled to the setpoint +5% of
the sensor’s range.
(Blank)
F
Loop is set to SKIP.
Sensor has failed.
The next table explains the symbols you see on the bottom line of the
Bar Graph display and in the Single Loop display. These symbols
appear when the controller is in both dual output mode and single output
mode. If the process goes into alarm, the controller automatically
switches to Single Loop display and shows an alarm code.
MLS User’s Guide 51
Using the MLS
Bar Graph
DisplaySy
mbol
Single
Loop
DisplaySy
mbol
Description
M
MAN
One or both outputs enabled. Loop is in manual control.
A
AUTO
Only one output (Heat or Cool) is enabled. Loop is in automatic
control.
T
TUNE
Indication that the loop is in Autotune mode.
H
T
HEAT
Both heat and cool outputs are enabled. Loop is in Automatic
control and heating.
C
L
COOL
Both heat and cool outputs are enabled. Loop is in Automatic
control and cooling.
(blank)
(blank)
Both outputs disabled, or input type is set to SKIP.
Navigating in Bar Graph Display
Press the Yes (up) or No (down) key to see a new group.
• Press Enter twice to scan all groups. The groups will display sequentially for three seconds each. This is called Scanning Mode.
• Press Back, Yes or No to go back to Bar Graph display.
• From Bar Graph display, press Back once to go to Single Loop display.
Viewing One Loop: Single Loop Display
Single Loop display (below) shows detailed information for only one
loop. If the heat and cool outputs are enabled, Single Loop display looks
like this:
Process Variable
Loop Number
or Name
Setpoint
LOOP
02
180
PROCESS
UNITS
160 ºF
AUTO 100
ALARM SETPOINT
STATUS
OUT%
Engineering
Units
Output
percentage
Control Status
The control status indicator shows HEAT or COOL if the loop is in
automatic control, and MAN or TUNE if the loop is in manual control.
52 MLS User’s Guide
Using the MLS
If only one output is enabled (heat or cool, but not both), Single Loop
display looks like this:
Engineering Units
Process Variable
Loop Number
Output Percentage
LOOP
PROCESS UNITS
or Name
Cool
02
160 ºF
0
180 AUTO 100
Output Percentage
Setpoint
ALARM SETPOINT STATUS OUT%
Heat
Control Status
Navigating in Single Loop Display
From the single loop display,
• Press the Back key once to get back to Bar Graph display.
• Press Enter twice to get to the Single Loop Scanning display. (The
Single Loop Scanning display shows information for each loop in
sequence. Data for each loop displays for one second.)
• Press Back, Yes, or No to return to the Single Loop display.
Interpreting Alarm Display
If an alarm occurs, the alarm interrupts any other display and switches
to the alarm display, as shown in the next figure. If the MLS is in Bar
Graph display, it switches to Bar Graph Alarm display. If it is in Single
Loop display, it switches to Single Loop Alarm display.
Loop Number
or Name
Alarm Symbols
LOOP
PROCESS
UNITS
01
AAAA
08
MAMA
ALARM SETPOINT
STATUS
Process Variable
LOOP
Loop number
or Name
02
LP
PROCESS
Alarm Symbols
Engineering Units
UNITS
ºF
180
180 AUTO 0
ALARM SETPOINT
Loop Status
OUT%
STATUS
Output Percentage
OUT%
Setpoint
MLS User’s Guide 53
Using the MLS
This table shows the symbols used in each form of the alarm display.
Bar Graph
Symbol
Single Loop
Symbol
Description
>
HP
High Process Alarm
>
HD
High Deviation Alarm
<
LP
Low Process Alarm
<
LD
Low Deviation Alarm
B
T/C Break
Open Input Error
S
O
RTD Short
RTD Open
RTD Short Alarm
RTD Open Alarm
Aim Comm
Failure
Aim Fail
MLS-AIM
Communications Failure
Acknowledging an Alarm
Press Alarm Ack to acknowledge the alarm. If there are other loops
with alarm conditions, the Alarm display switches to the next loop in
alarm. Acknowledge all alarms to clear the global alarm digital output
(The keyboard and display won't work for anything else until you
acknowledge each alarm). The alarm symbols are displayed as long as
the alarm condition is valid.
54 MLS User’s Guide
Using the MLS
Displaying, Loading, and Saving Jobs
Job display appears only if:
• You have turned on the Remote Job Select function. (This function is
explained in Chapter 4: Setup.)
• You have selected a job from the job load menu.
When you load a job, Job display shows you the following screen:
LOOP
PROCESS
UNITS
JOB 3 RUNNING
ALARM SETPOINT
STATUS
OUT%
If you remotely loaded the job, Job display looks like this:
LOOP
PROCESS
UNITS
JOB 3 RUNNING
REMOTELY LOADED
ALARM SETPOINT
STATUS
OUT%
If you modify a job's parameters while the job is running, you'll see this
job message:
LOOP
PROCESS
UNITS
JOB 3 RUNNING
DATA MODIFIED
ALARM SETPOINT
STATUS
OUT%
If an alarm occurs, the controller switches to Single Loop Display.
MLS User’s Guide 55
Using the MLS
Operator Menus
You can perform these tasks from Single Loop Display.
Changing the Setpoint
Press Chng SP from the loop you want to change. this display appears:
LOOP
PROCESS
UNITS
01 SETPOINT ?
25
ALARM SETPOINT
STATUS
OUT%
• Press Yes to change the setpoint.
• Press Yes or No to change the setpoint value.
• Press Enter to save your changes and return to Single Loop Display.
• Press No or Back to return to Single Loop Display without saving
the new setpoint.
Selecting Manual, Automatic, or Tune Control
Press Man/Auto.
• If you set the output mode to Auto, the MLS automatically controls
the process according to the configuration information you give it.
• If you set the output mode to Manual, you need to set the output
level.
• If you set the output mode to Tune, you can tune the PID parameters.
If the Loop is in Manual Mode
• Press Yes to toggle the mode.
• Press No to skip the mode change menu and set the output level. (See
the Manual Output Levels section for instructions.)
• Press Back to return to the single loop display without saving the
new mode setting.
• Press Enter to save your changes and return to single loop display.
If the loop is in Automatic Mode
• Press Yes to toggle the mode.
• Press Back or No to return to single loop display without saving your
changes.
• Press Enter to save your changes and if you have selected Manual
Mode, set the output level. (To learn how to set the output level, see
Manual Output Levels.)
56 MLS User’s Guide
Using the MLS
• Press Enter, then Back to store the new mode and return to Single
Loop Display without setting an output level.
NOTE
If the loop outputs are disabled, you cannot toggle
between Manual and Automatic output control. If
you try it, the screen shows an error message telling you that the outputs are disabled, as shown
below.
Use the menus in the Setup Loop Outputs main
menu to enable the outputs. (See Chapter 4: Setup
for more information about the Setup menus.)
LOOP
PROCESS
UNITS
MAN/AUTO CONTROL
OUTPUTS DISABLED
ALARM SETPOINT
STATUS
OUT%
Setting the Manual Output Levels
You'll only see this menu if you set the current loop to Manual control.
Use this menu to set the manual heat and cool output levels. (The cool
output level menu will only be present if the cool output for the current
loop is enabled; see Outputs Enabled/Disabled in Chapter 4: Setup).
You should see a display like this:
LOOP
PROCESS
UNITS
01 SET HEAT
OUTPUT ? 90%
ALARM SETPOINT
STATUS
OUT%
• Press Yes to change the output power level. (If the MLS' heat outputs
are enabled, you will be able to change the heat output power level.
If only the cool outputs are enabled, you will be able to change only
the cool output power level.)
• Then press Yes or No to select a new output power level.
• When you are satisfied with the power level you have chosen, press
Enter to store your changes.
• Then press No to advance to the cool output menu (if the cool outputs on the MLS are enabled).
• Press Back at any time to discard your changes and return to single
loop display.
MLS User’s Guide 57
Using the MLS
Automatically Tuning a Loop
When you use the Autotune function, the controller automatically sets
the loop to Manual control, 100% output. (If you selected a continuous
output limit, the controller sets the loop to the output limit.) The
autotune function calculates the appropriate PID constants for the loop
and puts the loop in automatic control with the calculated PID values.
The Autotune function will abort if:
• The process variable goes over 75% of the setpoint. (Remember, the
controller is at 100% output or at the output limit you set.)
• The controller has not calculated PID constants after 10 minutes (due
to heater failure, sensor failure, etc.).
If the autotune function aborts, it puts the loop into its previous control
state (Automatic or Manual control) at the previous output percentages.
To automatically tune a loop, follow these steps:
1. Make sure the process is cold (or stable and well below setpoint).
2. Initiate Autotune:
1. Use the front panel keypad to go to Single Loop Display.
2. Press the Man/Auto key.
3. Choose Tune.
4. Press Enter.
The Tune indicator will flash and the controller will return to Single
Loop Display. The Tune indicator will flash as long as the loop is
tuning.
58 MLS User’s Guide
Setup
The Setup menus let you change the MLS' detailed configuration
information.
If you have not set up a Modular Loop System before, or if you don't
know what values to enter, please read first the next chapter, Tuning and
Control which contains PID tuning constants and useful starting values.
How to enter the Setup menus?
1. In Single Loop Display, select the loop you wish to edit.
2. While still in Single Loop Display, enter the pass sequence below:
Press Enter, Alarm Ack, Change Setpoint.
3. The first setup menu appears.
NOTE
For your protection, MLS reverts to Single Loop Display If you don't make any changes for three minutes.
How to edit a menu?
• Press Yes to select this menu or No to advance to the next menu.
• press Yes or No to toggle between the options in your menu.
• Press Enter to store the value you have selected.
• If you decide not to edit the menu, press Back to stop editing and
return to the main menu.
In the next sections you will find detailed information about the
submenus for each of the six main menus.
Each display contains the default value for that specific menu, and
below each display you will see the range of choices for that menu.
The next page shows a diagram describing the six main menus and all
the submenus in each one of them.
MLS User’s Guide 59
Setup
Setup Loop xx
Input?
Setup Global
Parameters?
save setup to
job?
Load setup from
job?
Input type?
Pulse sample time?
Loop name?
Job control
dig inputs?
Job digital input
true?
Output override
dig input?
Input units?
Input reading
offset (T/C &
RTD)?
Override dig
in active?
Startup alarm
delay?
Disp format
(Linear & Pulse)?
Input scaling
Hi pv? (Linear &
Pulse)
Keyboard lock
status?
Input scaling
Hi rdg? (Linear &
Pulse)
Power up output
status?
Input scaling
Lo pv? (Linear &
Pulse)
Input scaling
Lo RDG? (Linear
& Pulse)
Controller
address?
Communications
err check?
Communications
baud rate?
Allen Bradley
protocol?
Setup Loop xx
Control Params?
Heat control PB?
Heat control TI?
Heat control TD?
Heat control filter?
Cool control PB?
Cool control TI?
60 MLS User’s Guide
Heat output
type?
Heat output
cycle time? (TP)
SDAC menus
(SDAC)
Heat output
action?
Cool control filter?
Heat/Cool
spread?
Lo pass filter
value?
Press Enter, Alarm Ack, Change
Press Yes to use a menu.
value or select an option.
have changed.
Press Back to escape a menu
EPROM
information
High process
alarm setpoint?
Heat output
limit time?
Press Enter to store the value you
AIM comm.
failure output?
Heat control out?
Heat output
limit?
Press Up or Down to change a
Digout outputs
active?
Setup Loop
xx Alarms?
Cool control TD?
Setpoint to reach these menus.
AC line freq?
Setup loop xx
Outputs?
Keypad test?
High process
alarm dig out?
Test digital
output?
Deviation
alarm value?
High deviation
alarm type?
Alarm dig out?
Low deviation
alarm type?
Low deviation
alarm dig out?
Outputs heat
NLO?
Low process
alarm setpoint?
Cool control out?
Low process
alarm type?
Low process
alarm dig out?
Cool output
cycle time?
Alarm deadband?
SDAC menus
(SDAC)
Alarm delay?
Cool output
action?
Cool output
limit?
Cool output
limit time?
Sensor fail
Cl output?
without changing it.
Outputs cool
NLO?
Digital inputs?
High process
alarm type?
Sensor fail
Ht output?
Cool output
type?
Manual I/O
Test?
Digital output
number?
Setup
Setup Global Parameters Menu
The setup global parameters menu looks like this
LOOP
PROCESS
UNITS
SETUP GLOBAL
PARAMETERS?
ALARM SETPOINT
STATUS
OUT%
Below is the setup global parameters menu tree. Notice the default
values inside the boxes.:
Setup Global Parameters?
Power up output status?
OFF
Save setup to job? 1
Controller address?
1
Load setup from job? 1
Job control digital inputs?
NONE
Job digital input true?
LOW
Output override dig
input? NONE
Override dig in active?
LOW
Startup alarm delay?
0 MINS
Keyboard lock status?
OFF
Communications err
check? BCC
Communications baud
rate? 9600
Allen Bradley protocol?
NO
AC line freq.?
60 HERTZ
Digout outputs active?
LOW
AIM communications
failure output? NONE
EPROM information
MLS User’s Guide 61
Setup
Save to Job
Use this menu to save the job information for every loop to one of eight
jobs in the MLS’ battery-backed RAM.
LOOP
PROCESS
UNITS
SAVE SETUP
TO JOB? 1
ALARM SETPOINT
STATUS
OUT%
Selectable Range: 1-8.
If you have enabled the remote job control function, you will not be able
to save a job; when you try to do it, you will see this message:
LOOP
PROCESS
UNITS
CANNOT SAVE JOB
REMOTE SELECT
ALARM SETPOINT
STATUS
OUT%
Load from Job
Use this menu to load any one of eight saved jobs from the controller’s
front panel.
LOOP
PROCESS
UNITS
LOAD SETUP
FROM JOB? 1
ALARM SETPOINT
STATUS
OUT%
Selectable values: The last job number or job 1.
The following parameters are loaded as part of a job:
1. PID constants, filter settings, setpoints, and spread values.
2. Loop control status (Automatic or Manual), and output values (If the
loop is in Manual control).
3. Alarm functions (Off, Alarm, Control), setpoints, high/low process
setpoints, high/low deviation setpoints and deadband settings, and
loop alarm delay.
If you have enabled the remote job control function, this menu is
disabled.
62 MLS User’s Guide
Setup
Job Select Inputs
Use the Remote Job Control feature to run up to 8 jobs remotely. The
Job Select Inputs menu is the third menu under Setup Global
Parameters. It lets you set the number of job select inputs. The controller
uses these inputs as a binary code that specifies the job number to run.
The number of inputs you choose in this menu controls the number of
jobs you can select remotely. The menu looks like this:
LOOP
PROCESS
UNITS
JOB CONTROL DIG
INPUTS? NONE
ALARM SETPOINT
STATUS
OUT%
Selectable values: 1, 2, 3 , or NONE.
Below is the truth table that tells you which input states select which
jobs.
Digital
Input 3
Digital Input
2
Digital Input
1
Job #
F
F
F
1
F
F
T
2
F
T
F
3
F
T
T
4
T
F
F
5
T
F
T
6
T
T
F
7
T
T
T
8
You can choose 1, 2, or 3 inputs, or None. These choices have the
following effect:
Setting
Enables
1 input
Jobs 1-2
2 inputs
Jobs 1-4
3 inputs
Jobs 1-8
None (no inputs)
Remote Select disabled
MLS User’s Guide 63
Setup
Job Digital Input Polarity
Use this menu to set the polarity of the digital outputs used for job
selection. You can set the Active state to closed (Low) or open (High).
LOOP
PROCESS
UNITS
JOB DIGITAL INPUT
TRUE? LOW
ALARM SETPOINT
STATUS
OUT%
Selectable values: Low or High.
Output Override Digital Input
This menu lets you set a digital input that sets all loops in manual
output at output levels you select in the Outputs menu. This menu, and
the next one, let you configure a "panic button" or "kill switch" that sets
all outputs to the output override percentage you set in the Setup Loop
Outputs main menu.
LOOP
PROCESS
UNITS
OUTPUT OVERRIDE
DIG INPUT? NONE
ALARM SETPOINT
STATUS
OUT%
Selectable values: Input number 1-8, or NONE.
WARNING
ANAFAZE recommends that you install additional
external safety devices or over-temperature
devices for emergency shutdowns. Do not rely
solely on the output override feature to shut down
your process.
Output Override Input Polarity
This menu lets you toggle the polarity of the Output Override digital
input. You can set the input to be active when Low or active when High.
LOOP
PROCESS
UNITS
OVERRIDE DIG IN
ACTIVE? LOW
ALARM SETPOINT
STATUS
OUT%
Selectable values: Low or High.
64 MLS User’s Guide
Setup
Startup Alarm Delay
Use this menu to set a startup delay for process and deviation alarms for
all loops. The controller does not report these alarm conditions for the
specified number of minutes after the controller powers up. (The
controller will always report failed sensor alarms, no matter what startup
delay you set.)
LOOP
PROCESS
UNITS
STARTUP ALARM
DELAY? 0 mins
ALARM SETPOINT
STATUS
OUT%
Selectable Range: 0-60 minutes.
Keyboard Lock Status
Use this menu to lock the front panel operator function keys Change SP,
Man/Auto, and Ramp/Soak so that pressing these keys has no effect. If
you want to use these functions, turn off the Keyboard Lock.
LOOP
PROCESS
UNITS
KEYBOARD LOCK
STATUS? OFF
ALARM SETPOINT
STATUS
OUT%
Selectable values: On or Off.
Power-Up Output Status
Use this menu to set the initial power-up state of the control outputs to
Off or Memory. If you choose Off, all control outputs are initially set to
Manual mode at 0% output level. If you choose Memory, the outputs are
restored to the last output state stored in memory.
LOOP
PROCESS
UNITS
POWER UP OUTPUT
STATUS? OFF
ALARM SETPOINT
STATUS
OUT%
Selectable values: Off or Memory.
WARNING
Do not set the MLS to start from memory if a
memory-based restart is unsafe for your process.
MLS User’s Guide 65
Setup
Controller Address
Use this menu to set the MLS controller address. The controller address
is used for multiple controller communications on a single RS-485
cable, so each MLS must have a different address. Begin with address 1
for the first controller and assign each subsequent controller the next
higher address.
LOOP
PROCESS
UNITS
CONTROLLER
ADDRESS? 1
ALARM SETPOINT
STATUS
OUT%
Selectable Range: a number between 1 and 32.
Communications Error Checking
Use this menu to set the data check algorithm used in the ANAFAZE
communications protocol to Block Check Character (BCC) or to Cyclic
Redundancy Check (CRC).
CRC is a more secure error checking algorithm than BCC, but it
requires more calculation time and slows the MLS communications.
BCC ensures a high degree of communications integrity, so ANAFAZE
recommends that you use BCC unless your application specifically
requires CRC.
LOOP
PROCESS
UNITS
COMMUNICATIONS
ERR CHECK? BCC
ALARM SETPOINT
STATUS
OUT%
Selectable values: BCC or CRC.
NOTE
If you are using ANASOFT, be sure to configure
ANAINSTL for the same error checking method that
you set in this menu.
66 MLS User’s Guide
Setup
Communications Baud Rate
Use this menu to set the Communications Baud Rate to 2400 or 9600
baud.
LOOP
PROCESS
UNITS
COMMUNICATIONS
BAUD RATE? 9600
ALARM SETPOINT
STATUS
OUT%
Selectable values: 9600 or 2400.
NOTE
If you use ANASOFT, be sure to set ANAINSTL to
the same baud rate that you set in this menu.
Allen Bradley Protocol
Use this menu to set the protocol type to either Allen Bradley or
ANAFAZE.
LOOP
PROCESS
UNITS
ALLEN BRADLEY
PROTOCOL? NO
ALARM SETPOINT
STATUS
OUT%
Selectable values: Yes or No.
AC Line Frequency
Use this menu to configure the controller to match an AC line frequency
of 50 or 60 Hz. (This function is provided for international users who
require 50 Hz lines.) Since the controller reduces the effect of power
line noise on the analog measurement by integrating the signal over the
period of the AC line frequency, the controller's noise rejection will
suffer if the line frequency is not set correctly.
LOOP
PROCESS
UNITS
AC LINE FREQ ?
60 HERTZ
ALARM SETPOINT
STATUS
OUT%
Selectable values: 60 Hz or 50 Hz.
NOTE
If you change the AC line frequency, you must switch
power to the MLS on and off for the change to take
effect.
MLS User’s Guide 67
Setup
Digital Output Polarity
Use this menu to set the polarity of the digital outputs used for alarms.
The output can be active High or active Low.
LOOP
PROCESS
UNITS
DIGOUT OUTPUTS
ACTIVE? LOW
ALARM SETPOINT
STATUS
OUT%
Selectable values: High or Low.
AIM Communications Failure Output
Use this menu to select the digital output that activates if
communications fail between the MLS-AIM and the MLS-PM. You can
use this output, along with the Global Alarm output, to power an alarm
horn or buzzer that sounds if communications fail between the AIM and
the PM.
The global alarm will activate if there is an AIM communications
failure, and will reset automatically when the problem is corrected. The
controller will revert to manual mode during an AIM communications
failure.
LOOP
PROCESS
UNITS
AIM COMM FAILURE
OUTPUT? NONE
ALARM SETPOINT
STATUS
OUT%
Selectable values: any output from 1 to 34 as long as it’s not used for
control or for SDAC clock, or NONE.
EPROM Information
Use this last menu of the Setup Global Parameters main menu to see the
controller's EPROM version and checksum.
LOOP
PROCESS
UNITS
MLS
VO 2.60
ALARM SETPOINT
STATUS
OUT%
Press any key from this menu to return to the Setup Parameters menu.
68 MLS User’s Guide
Setup
Setup Loop Input
The Setup Loop Input main menu lets you access menus which change
loop input parameters:
• Input type
• Input scaling and calibration
• Input filtering
The next section explains how to configure inputs via the front panel.
LOOP
PROCESS
UNITS
SETUP LOOP 02
INPUT?
ALARM SETPOINT
STATUS
OUT%
Below is the menu tree for the Setup Loop Inputs menu. Notice the
default values inside the boxes.
Setup Loop Inputs?
T/C or RTD
Input Type?
J T/C
Linear & Pulse
pulse sample
time?
Loop’s name?
Loop’s name?
Input units? __
Input units? ºF
Disp format?
-9999 to 30000
Input reading
offset? 0ºF
Input scaling
Hi PV? 10000
Input scaling Hi
RDG? 100.0% FS
input scaling
Lo PV? -1660
Input scaling Lo
RDG? -16.6%FS
Low pass filter
value? 3
MLS User’s Guide 69
Setup
Input Type
Use this menu to configure the input sensor for each loop as one of these
input types:
• Thermocouple types (J, K, T, S, R and B).
• RTD. Three ranges: RTD1 (Platinum Class A), RTD2 (Platinum
Class B), and RTD3 (Nickel).
• Linear and Pulse inputs.
• Skip (an input type available for unused channels.) The scanning display doesn't show loops you've set to Skip.
LOOP
PROCESS
UNITS
06
INPUT TYPE?
J T/C
ALARM SETPOINT
STATUS
OUT%
The next table shows the MLS' input types and ranges.
70 MLS User’s Guide
Input
Type
Fahrenheit
Range
Celsius Range
J
-350 to +1400
-212 to +760
K
-450 to +2500
-268 to +1371
T
-450 to +750
-268 to +399
S
0 to +3200
-18 to +1760
R
0 to +3210
-18 to +1766
B
+150 to +3200
+66 to +1760
RTD1
-148.0 to +572.0
-100.0 to +300.0
RTD2
-184 to +1544
-120 to +840
RTD3
-94 to 572
-70 to 300
Pulse
0-2 KHz
Skip
Loop is not scanned or displayed.
Linear
see the Linear Scaling section (this chapter) and Appendix.
Setup
Pulse Sample Time
You can connect a digital pulse signal of up to 2 KHz to the controller’s
pulse input. Use this menu to specify the pulse sample period. Every
sample period, the number of pulses the controller receives is divided by
the sample time. The controller scales this number and uses it as the
pulse loop’s PV.
LOOP
PROCESS
UNITS
06 INPUT PULSE
SAMPLE TIME? 1s
ALARM SETPOINT
STATUS
OUT%
Selectable range: 1-20 seconds.
Loop Name
Use this menu to name your loop. You can choose any two characters
from the set of characters used for the input units.( See table below).
LOOP
PROCESS
UNITS
A5 LOOP SAMPLE NAME? A5
ALARM SETPOINT
STATUS
OUT%
Input Units
Use this menu to choose a three-character description of the loop's
engineering units.
LOOP
PROCESS
UNITS
06 INPUT
UNITS?
ºF
ALARM SETPOINT
STATUS
OUT%
Selectable values: This table shows the character set for input units.
Input
Character Sets for Units
thermocouples & RTDs
F or C degrees
Linear and Pulse
0-9, A-Z, %, degrees, /, space
MLS User’s Guide 71
Setup
Input Reading Offset
Use this menu to make up for the input signal's inaccuracy. For
example, at temperatures below 400 ºF, a type J thermocouple may be
inaccurate ("offset") by several degrees F. Use an independent
thermocouple or your own calibration equipment to find the offset for
your equipment. To correct for offset errors, change the factory default
setting to a positive or negative value for the loop you are editing. (A
positive value increases the reading and a negative value decreases it.)
LOOP
PROCESS
UNITS
06 INPUT READING
OFFSET? 0 º F
ALARM SETPOINT
STATUS
OUT%
Selectable range: -300 to +300.
NOTE
If the input type is Linear, Pulse, or Skip, you will not
see the Input Reading Offset menu.
Linear Scaling Menus
The linear scaling menus appear under the Setup Loop Inputs main
menu, and they are available for Linear and Pulse inputs only. It lets you
scale the "raw" input readings (readings in millivolts or hertz) to the
engineering units of the process variable.
You'll only see the linear scaling menus if you set the
loop's input type to Linear or Pulse.
For linear inputs, the input reading is in percent (-16.6 to 100%)
representing the -10-60 mV input range of the MLS. The scaling
function is defined by two points on a conversion line. It relates the high
PV to the high reading and the low PV to the low reading to define the
line. The engineering units of the process variable can be any arbitrary
units.
72 MLS User’s Guide
Setup
The graph below shows pressure as an example.
Before you enter the values that determine the two points for the
conversion line, you must choose an appropriate display format. The
MLS has six characters available for process variable display; select the
setting with the desired number of decimal places before and after the
decimal point. Use a display format that matches the range and
resolution of the process variable. The display format you choose is
used for the setpoint, alarms, deadband, spread, and proportional band.
The PV (Process Variable) range for the scaled input is between the PV
values that correspond to the -16.6% and 100% input readings. This PV
range defines the limits for the setpoint and alarms, as shown here.
Hi PV
Proce s s
Variable
Range
Lo PV
0 PS I
0%
0 mV
0 Hz
Lo
RDG
Input Re ading
100%
Hi
Line ar input type
RDG 60 mV
2000 Hz } Puls e input type
}
NOTE
See Linear Scaling Examples section in this manual.
MLS User’s Guide 73
Setup
Display Format
Use this menu to select a display format for a linear input. Choose a
format appropriate for your input range and accuracy.
LOOP
PROCESS
UNITS
05 DISP FORMAT
-9999 TO 30000
ALARM SETPOINT
STATUS
OUT%
Selectable values: The MLS has several available display formats, as
shown below. this table shows also the high and low PV values. .
Display Formats
High PV Default
Low PV Default
-9999 to +30000
10000
0
-999 to +3000
1000
0
-99 to +300
100
0
-9 to +30
10
0
-.9999 to +3.0000
1.0000
.0000
-9.999 to +30.000
10.000
.000
-99.99 to +300.00
100.00
.00
-999.9 to +3000.0
1000.0
.0
High Process Value
Use this menu to enter a high process value. The high process value and
the high reading value together define one of the points on the linear
scaling function's conversion line.
LOOP
PROCESS
UNITS
01 INPUT SCALING
HI PV? 10000 º F
ALARM SETPOINT
STATUS
OUT%
Selectable values: See table above.
74 MLS User’s Guide
Setup
High Reading
Use this menu to enter the input level that corresponds to the high
process value you entered in the previous menu. For linear inputs, the
high reading is a percentage of the full scale input range. For pulse
inputs, the high reading is expressed in Hz.
The 100% full scale input value is 60 mV for the linear input type.
LOOP
PROCESS
UNITS
09 INPUT SCALING
HI RDG = 100.0% FS
ALARM SETPOINT
STATUS
OUT%
Selectable range: Any value between -99.9 and 110.0. For pulse input,
the range is 0-2000 Hz, and the default is 1000 Hz.
Low Process Value
Use this menu to set a low process value for input scaling purposes. The
low process value and the low reading value together define one of the
points on the linear scaling function's conversion line.
LOOP
PROCESS
UNITS
02 INPUT SCALING
LO PV? 0 º F
ALARM SETPOINT
STATUS
OUT%
Selectable values: See table on previous page.
Low Reading
Use this menu to enter the input level that corresponds to the low
process value you selected in the previous menu. For linear inputs, the
low reading is a percentage of the full scale input range. For pulse
inputs, the low reading is expressed in Hz.
LOOP
PROCESS
UNITS
12 INPUT SCALING
LO RDG ? .-16.6%FS
ALARM SETPOINT
STATUS
OUT%
The full scale input range for the linear input type is -10 to 60 mV,
which corresponds to -16.6 to 100.0%.
Selectable range: Any value between - 99.9 and 110.0. For pulse
inputs, the range is 0-2000 Hz, and the default is 0.
MLS User’s Guide 75
Setup
Input Filter
Access this menu from the Setup Loop Inputs main menu. The MLS has
two different types of input filter:
• A noise rejection filter that rejects high frequency input signal noise.
This filter keeps a "trend log" of input readings. If a reading is outside the filter's "acceptance band", and later readings are within the
acceptance band, the MLS ignores the anomalous reading. (The
acceptance band for thermocouples is 5 degrees above and 5
degrees below the input reading. For linear inputs, it's 0.5% above
and 0.5% below the input reading.) If later readings are also outside
the acceptance band, the MLS accepts the anomalous reading and
calculates a new acceptance band. (This input filter does not require
adjustment.)
• A standard resistor-capacitor (RC) filter that lets you dampen the
input response if inputs change unrealistically or change faster than
the system can respond. If the input filter is enabled, the process
variable responds to a step change by going to 2/3 of the actual
value within the number of scans you set.
If all input loops are enabled (none of them are set to SKIP) the MLS
scans each input loop 2 times per second. The input filter applies to all
input types except those set to SKIP.
LOOP
PROCESS
UNITS
01 LOW PASS FILTER
VALUE? 3 SCANS
ALARM SETPOINT
STATUS
OUT%
Selectable range: 0-255 scans.
76 MLS User’s Guide
Setup
Setup Loop Control Parameters
Use these menus to change control parameters for heat and cool outputs
of the selected loop, including:
• Proportional Band (PB), Integral (TI or Reset), and Derivative (TD
or Rate) settings.
• Output Filter.
• Spread between heat and cool outputs.
The Setup Loop Control Parameters menu looks like this:
LOOP
PROCESS
UNITS
SETUP LOOP 01
CONTROL PARAMS?
ALARM SETPOINT
STATUS
OUT%
NOTE
Both heat and cool outputs have the same menus, so
only one of each menu is explained in the text. The
controller shows both heat and cool menus even if the
heat or cool output is disabled. (See Setup Loop Outputs for help in enabling or disabling the heat or cool
output.)
Refer to Tuning and Control section for help in
selecting control parameter values.
Setup Loop Control
Parameters?
Heat control PB?
50ºF
Heat control TI?
60 Sec/R
Heat control TD?
0 Sec.
Heat control filter?
2
Cool control PB?
50ºF
Cool control TI?
60 Sec/R
Cool control TD?
0 Sec.
Cool control filter?
2
Heat / Cool
spread? 5ºF
MLS User’s Guide 77
Setup
Heat/Cool Control PB
Use this menu to set the Proportional Band.
LOOP
PROCESS
UNITS
01 HEAT CONTROL
PB? 50 ºF
ALARM SETPOINT
STATUS
OUT%
NOTE
The MLS internally represents the proportional band
(PB) as a gain value. When you edit the PB, you'll see
the values change in predefined steps--small steps for
narrow PB values and large steps for wide PB values.
The controller calculates the default PB for each input type according to
the following equation:
(High Range - Low Range)
Default PB =
Gain
Heat/Cool Control TI
Use this menu to set the Integral term, or Reset.
LOOP
PROCESS
UNITS
01 HEAT CONTROL
TI ? 180 SEC/R
ALARM SETPOINT
STATUS
OUT%
Selectable range: 0-6000 seconds.
Heat/Cool Control TD
Use this menu to set the derivative constant.
LOOP
PROCESS
UNITS
15 HEAT CONTROL
TD ? 0 SEC
ALARM SETPOINT
STATUS
OUT%
Selectable range: 0-255 seconds.
78 MLS User’s Guide
Setup
Heat/Cool Output Filter
Use this menu to dampen the heat or cool output's response. The output
responds to a step change by going to approximately 2/3 of its final
value within the number of scans you set here.
LOOP
PROCESS
UNITS
07 HEAT CONTROL
FILTER ? 2
ALARM SETPOINT
STATUS
OUT%
Selectable range: 0-255. Setting the output filter to 0 turns it off.
Heat/Cool Spread
Use this menu to set the spread between the heat and cool output and the
spread of the On/Off control action.
LOOP
PROCESS
UNITS
01 HEAT
SPREAD ? 5 ºF
ALARM SETPOINT
STATUS
OUT%
Selectable range: The spread ranges from 0 to 255, 25.5, 2.55, .255 or
.0255, depending on the way you set up the input menus.
MLS User’s Guide 79
Setup
Setup Loop Outputs
Press Yes at this prompt to access menus to change loop output
parameters for the current loop, including:
• Enable or disable outputs
• Output type
• Cycle time (for TP outputs)
• SDAC parameters (for SDAC outputs)
• Control action
• Output level limit and limit time
• Output override
• Nonlinear output curve
Both heat and cool outputs have the same menus, so only one of each
menu is explained in this section. (The next page shows a menu tree.)
Here's the main menu:
LOOP
PROCESS
UNITS
SETUP LOOP 03
OUTPUTS ?
ALARM SETPOINT
STATUS
OUT%
The figure on the next page shows the menu tree for the output setup
menus. Notice the default values inside the boxes
80 MLS User’s Guide
Setup
Setup Loop Outputs?
Output disabled
Heat/Cool control out?
Output
Enabled
For TP outputs
For SDAC outputs
Heat/cool output
cycle time? 10 S
For ON/OFF DZC
Heat/Cool output type?
SDAC mode?
Voltage
SDAC Lo value?
0.00
SDAC Hi value?
10.00 VDC
Heat/Cool output action?
Reverse
Heat/Cool output limit?
100%
Heat/Cool output limit
time? CONT
Sensor fail Heat/Cool
output? 0%
Outputs Heat/Cool NLO?
OFF
MLS User’s Guide 81
Setup
Enable/Disable Heat and Cool Outputs
Use this menu to enable or disable the heat or cool output for the current
loop. If you want the loop to have PID control, you must enable one
output. You can also disable a heat or cool control output and use the
output pin for something else, like an alarm.
LOOP
PROCESS
UNITS
05 HEAT CONTROL
OUT? ENABLED
ALARM SETPOINT
STATUS
OUT%
Selectable values: Enabled or Disabled. The default setting enables the
heat outputs and disables the Cool outputs.
Heat or Cool Output Type
Use this menu to set the output type. .
LOOP
PROCESS
UNITS
14 HEAT OUTPUT
TYPE = TP
ALARM SETPOINT
STATUS
OUT%
The next table shows the available output types.
Display
Code
Output
Type
TP
Time
Proportioning
Percent output converted to a percent duty
cycle over the programmed cycle time.
DZC
Distributed
Zero Crossing
Output on/off state calculated for every AC line
cycle.
SDAC
Serial DAC
ON/OFF
On / Off
Definition
Output type for optional Serial Digital-Analog
Converter (SCAC)
Output either full ON of full OFF.
For an expanded description of these output types, see Tuning and
Control.
82 MLS User’s Guide
Setup
Heat/Cool Cycle Time
Use this menu to set the Cycle Time for Time Proportioning outputs.
LOOP
PROCESS
UNITS
03 HEAT OUTPUT
CYCLE TIME ? 10S
ALARM SETPOINT
STATUS
OUT%
Selectable range: 1-255 seconds.
NOTE
The Cycle Time menu will only be present if the output type for the current loop is Time Proportioning.
SDAC Menus
If you attach the optional SDAC to an output, you must configure that
output for the SDAC using the following series of menus. The MLS will
also assign digital output #34 as a clock line for the SDAC. You won't be
able to assign another function to output #34 while any loop's output is
set to SDAC.
SDAC Mode
Use this menu to toggle the SDAC between current and voltage output.
The SDAC menus only appear if the output type for the loop is set to
SDAC.
LOOP
PROCESS
UNITS
01 SDAC MODE ?
VOLTAGE
ALARM SETPOINT
STATUS
OUT%
Selectable values: Current and Voltage.
MLS User’s Guide 83
Setup
SDAC High Value
Use this menu to set a high value for the SDAC output. Set the high and
low value to match the range of the output device. For instance, if the
output device has a 4-20 mA range, set the SDAC high value to 20.00
mA and the SDAC low value to 4.00 mA. The controller converts 0%
output to a 4.00 mA signal and 100% output to a 20.00 mA signal.
LOOP
PROCESS
UNITS
03 SDAC HI VALUE ?
10.00 VDC
ALARM SETPOINT
STATUS
OUT%
Selectable values: If the output is set to Voltage, the default high value
is 10.00 volts. If the output is set to Current, the default high value is
20.00 mA. You cannot set the high value to be less than or equal to the
low value.
SDAC Low Value
Use this menu to set a low value for the SDAC output. Set the high and
low value to match the range of the output device. For instance, if the
output device has a 0.00-10.00 Vdc range, set the SDAC high value to
10.00 Vdc and the SDAC low value to 0.00 Vdc. The controller converts
0% output to a 0.00 Vdc signal and 100% output to a 10.00 Vdc signal.
LOOP
PROCESS
UNITS
04 SDAC LO VALUE ?
0.00 VDC
ALARM SETPOINT
STATUS
OUT%
Selectable values: If the output is set to Voltage, the default low value is
0.00 volts. If the output is set to Current, the default value is 4.00 mA.
You cannot set the low value to be greater than or equal to the high
value.
Heat/Cool Output Action
Use this menu to select the control action for the current output loop.
Normally, heat outputs are set to reverse action and cool outputs are set
to direct action.
LOOP
PROCESS
UNITS
01 HEAT OUTPUT
ACTION ? REVERSE
ALARM SETPOINT
STATUS
OUT%
Selectable values: Reverse or Direct.
For Heat outputs, set to Reverse; for Cool outputs, set to Direct.
84 MLS User’s Guide
Setup
Heat/Cool Output Limit
Use this menu to limit the maximum PID control output for a loop's heat
and cool outputs. This limit may be continuous, or it may be in effect for
a specified number of seconds (see Output Limit Time on the next
page). If you choose a timed limit, the output limit restarts when the
controller powers up and when the output goes from Manual to
Automatic control (via the front panel, when the controller changes
jobs, or from ANASOFT.) The output limit only affects loops under
automatic control. It does not affect loops under manual control.
LOOP
PROCESS
UNITS
01 HEAT OUTPUT
LIMIT ? 100%
ALARM SETPOINT
STATUS
OUT%
Selectable range: 0-100%
Heat/Cool Output Limit Time
Use this menu to set a time limit for the output limit.
LOOP
PROCESS
UNITS
04 HEAT OUTPUT
LIMIT TIME ? CONT
ALARM SETPOINT
STATUS
OUT%
Selectable values: 1-999 seconds, or CONT (continuous).
Heat/Cool Output Override
Use this menu to set an output override percentage. (You can configure a
digital input for the output override in the Setup Global Parameters main
menu.) If the current loop is in Automatic mode and a sensor failure
occurs, the loop switches to the output override percentage, manual
mode. If you change the polarity of the override output to the active
state--for instance, by flipping a "kill switch" you have set up--every
loop switches to the output override percentage you set here.
LOOP
PROCESS
UNITS
03 SENSOR FAIL
HT OUTPUT ? 0%
ALARM SETPOINT
STATUS
OUT%
Selectable range: 0-100%
MLS User’s Guide 85
Setup
Heat/Cool Nonlinear Output Curve
Use this menu to select one of two nonlinear output curves for nonlinear
processes.
LOOP
PROCESS
UNITS
03 OUTPUTS HEAT
NLO ? OFF
ALARM SETPOINT
STATUS
OUT%
Selectable values: Curve 1, Curve 2, or Off (linear/no curve).
The linear curves are shown in the figure below. Calculated by PID
100
100
90
80
80
Line ar
Output
60
70
66
62
60
50
1
40
48
44
40
36
30
29
27
20
20
19
19
13
10
0
0
3
8
2
12
7
4
2
Calculated by PID
86 MLS User’s Guide
79
Setup
Setup Loop Alarms
Press Yes at the Setup Loop Alarms prompt to access menus which
change alarm function parameters for the current loop. The main alarms
menu looks like this:
LOOP
PROCESS
UNITS
SETUP LOOP 04
ALARMS ?
ALARM SETPOINT
STATUS
OUT%
Below is the alarms menu tree. Notice the default values inside the
boxes.
Setup Loop Alarms?
High process
alarm setpoint?
1000ºF
High process
alarm type?
OFF
High process alarm
dig out? NONE
Low deviation
alarm type? OFF
Low deviation
alarm dig out?
NONE
Low process
alarm setpoint?
0ºF
Low process
alarm type? OFF
Deviation alarm
value? 5ºF
Low process
alarm dig out?
NONE
High deviation
alarm type? OFF
Alarm deadband?
2ºF
High deviation
alarm dig out?
NONE
Alarm delay?
0 Seconds
MLS User’s Guide 87
Setup
Alarm Types
The MLS has three different kinds of alarms: failed sensor alarms,
global alarms, and process alarms.
Failed Sensor Alarms
Failed sensor alarms alert you to T/C breaks and these RTD open or
short failures:
• Open + or - input.
• Short between + and - input.
When the loop is in Automatic or Tune mode and a failed sensor alarm
occurs, the MLS sets the loop to Manual control at the failed sensor
percentage you set in the Setup Loop Outputs menus.
Global Alarms
Global alarms occur when a loop alarm, set to Alarm (not Control), is
unacknowledged, or when there are any unacknowledged failed sensor
alarms. (If an alarm occurs, the MLS front panel displays an appropriate
alarm code--see Chapter 4: Using the MLS for an explanation of these
codes.) Even if the alarm condition goes away, the global alarm stays on
until you use the Alarm Ack key (or ANASOFT) to acknowledge it.
Process Alarms
Process alarms include high and low deviation and high and low process
alarms. You can set each of these alarms to Off, Alarm, or Control, as
shown here.
Function
Off
Alarm
Control
Description
No alarm or control function
Standard alarm function
Normal alarm function, except that you
don’t have to ackowledge alarms
• High process and high deviation alarms activate when the process
variable goes above a value you set. They remain active until the
process variable goes below that value minus the deadband. (See
the diagram on the next page.)
• If you don’t use a digital output for PID control, you can assign it to
one or more process variable alarms. The output is active if any of
its alarms are active. All alarm outputs are active Low or active
High, depending on the global alarm output polarity setting.
• Low process and low deviation alarms activate when the process
variable goes below a value you set. They remain active until the
process variable goes above that value plus the deadband. (The diagram below shows these alarms.)
88 MLS User’s Guide
Setup
When the controller powers up or the setpoint changes, deviation alarms
do not activate until the process goes inside the deviation alarm band-preventing deviation alarms during a cold start. (High and low process
alarms are always enabled.)
High process alarm on
High process alarm off
High Alarm Limit
} Deadband
High deviation alarm on
SP + Deviation
} Deadband
High deviation alarm off
Setpoint
Low deviation alarm off
} Deadband
SP - Deviation
Low deviation alarm on
} Deadband
Low Alarm Limit
Low process alarm on
Low process alarm off
Use menus to set the following process alarm parameters for each loop:
• High and low process alarm type, setpoint, and digital output.
• High and low deviation alarm type, deviation alarm value, and alarm
digital output.
• Alarm deadband.
• Loop alarm delay.
The setpoints, deviation alarm values, and deadband all use the same
decimal format as the loop's process variable.
MLS User’s Guide 89
Setup
Alarm Delay
You can set the MLS to delay normal alarm detection and alarm
reporting. There are two kinds of alarm delay:
• The startup alarm delay delays process alarms (but not failed sensor
alarms) for all loops for a time period you set in the Setup Global
Parameters main menu.
• The loop alarm delay delays failed sensor alarms and process alarms
for one loop until the alarm condition is continuously present for
longer than the loop alarm delay time you set.
NOTE
Failed sensor alarms are affected by the loop alarm
delay even during the startup alarm delay time period.
90 MLS User’s Guide
Setup
High Process Alarm Setpoint
Use this menu to select the setpoint (temperature or other value within
the scaled sensor range) at which the high process alarm activates. The
high process alarm activates when the process variable (PV) goes above
the high process setpoint. It deactivates when the PV goes below the
high process setpoint minus the deadband value, if you have set a
deadband value.
LOOP
PROCESS
UNITS
04 HI PROC ALARM
SETPT ? 1000 ºF
ALARM SETPOINT
STATUS
OUT%
Selectable range: Any point within the scaled sensor range.
High Process Alarm Type
Use this menu to turn off the high process alarm or set it to the alarm or
control function.
LOOP
PROCESS
UNITS
01 HI PROC ALARM
TYPE ? OFF
ALARM SETPOINT
STATUS
OUT%
Selectable values: Alarm, Control, Off.
High Process Alarm Output Number
Use this menu to choose the digital output that activates when the loop
is in high process alarm. You can use this output to activate a second
alarm horn or buzzer. You can also use it to control your process. For
example, you can set the output you have chosen to activate heating or
cooling mechanisms, or to turn off the system.
LOOP
PROCESS
UNITS
01 HI PROC ALARM
DIG OUT ? NONE
ALARM SETPOINT
STATUS
OUT%
Selectable values: Any output number between 1 and 34, as long as it’s
not already used for control or the SDAC clock. You may also select
NONE.
MLS User’s Guide 91
Setup
NOTE
All digital outputs are "OR'ed" together (combined).
Therefore you can assign more than one alarm to the
same output number, and that output will be On if any
of those alarms is On.
Deviation Band Value
Use this menu to set the deviation bandwidth, a positive and negative
alarm or control point relative to the setpoint. If the setpoint changes,
the alarm or control points also change. You can assign a separate digital
output to the high and low deviation alarm/control setpoints- so that, for
example, a high deviation alarm turns on a fan and a low deviation alarm
turns on a heater.
LOOP
PROCESS
UNITS
02 DEVIATION ALARM
VALUE ? 5ºF
ALARM SETPOINT
STATUS
OUT%
Selectable values: You can set a value from 0 to 255, 25.5, 2.55, .255 or
.0255, depending on how you set up the input menus.
High Deviation Alarm Type
Use this menu to disable the high deviation alarm function or set it to the
alarm or control function. (The high deviation alarm activates if the
process value (PV) rises above the deviation band value, and remains
active until the PV goes below the deviation band value minus the
deadband value.)
LOOP
PROCESS
UNITS
07 HI DEVIATION
ALARM TYPE ? OFF
ALARM SETPOINT
STATUS
OUT%
Selectable values: Alarm, Control, Off.
92 MLS User’s Guide
Setup
High Deviation Alarm Output Number
Use this menu to assign a digital output which activates when the loop is
in high deviation alarm. The digital output only activates if you have set
the high deviation alarm type to Alarm or Control.
LOOP
PROCESS
UNITS
01 HI DEV ALARM DIG
OUT ? NONE
ALARM SETPOINT
STATUS
OUT%
NOTE
All digital outputs are "OR'ed" together (combined).
Therefore you can assign more than one alarm to the
same output number, and that output will be On if any
of those alarms is On.
Selectable range: Any output number between 1 and 34, as long as it
isn’t used for control or the SDAC clock. You may also select NONE.
Low Deviation Alarm Type
Use this menu to turn Off the low deviation alarm or set it to Alarm or
Control mode.
LOOP
PROCESS
UNITS
12 LO DEVIATION
ALARM TYPE ? OFF
ALARM SETPOINT
STATUS
OUT%
Selectable values: Alarm, Control, Off.
Low Deviation Alarm Output Number
Use this menu to assign a digital output that activates when the loop is in
low deviation alarm.
LOOP
PROCESS
UNITS
12 LO DEV ALARM
DIG OUT? NONE
ALARM SETPOINT
STATUS
OUT%
Selectable values: Any output number between 1 and 34, as long as it
isn’t used for control or the SDAC clock. You may also select NONE.
MLS User’s Guide 93
Setup
NOTE
All digital outputs are "OR'ed" together (combined).
Therefore you can assign more than one alarm to the
same output number, and that output will be On if any
of those alarms is On.
Low Process Alarm Setpoint
Use this menu to set a low process alarm setpoint. (The low process
alarm activates when the process variable goes below the low process
alarm setpoint. It deactivates when the process variable goes above the
low process alarm setpoint plus the deadband.)
LOOP
PROCESS
UNITS
01 LO PROC ALARM
SETPT ? 0 ºF
ALARM SETPOINT
STATUS
OUT%
Selectable range: Any value within the input sensor’s range.
Low Process Alarm Type
Use this menu to turn off the low process alarm or set it to the Alarm or
Control function.
LOOP
PROCESS
UNITS
01 LO PROC ALARM
TYPE ? OFF
ALARM SETPOINT
STATUS
OUT%
Selectable values: Alarm, Control, Off.
Low Process Alarm Output Number
Use this menu to assign the digital output that activates when the loop is
in low process alarm.
LOOP
PROCESS
UNITS
04 LO PROC ALARM
DIG OUT ? 31
ALARM SETPOINT
STATUS
OUT%
Selectable values: Any output number between 1 and 34, as long as it
isn’t used for control or the SDAC clock. You may also select NONE.
94 MLS User’s Guide
Setup
NOTE
All digital outputs are "OR'ed" together (combined).
Therefore you can assign more than one alarm to the
same output number, and that output will be On if any
of those alarms is On.
Alarm Deadband
Use this menu to set an alarm deadband. This deadband value applies to
the high process, low process, high deviation, and low deviation alarms
for the loop you are editing. Use the Alarm Deadband to avoid repeated
alarms as the PV cycles slightly around an alarm value.
LOOP
PROCESS
UNITS
03 ALARM
DEADBAND ? 2 ºF
ALARM SETPOINT
STATUS
OUT%
Selectable values: The default range is 0 to 255, 25.5, 2.55, .255, or
.0255, depending on how you set up the input menus.
Loop Alarm Delay
Use this menu to set a loop alarm delay. There are two types of alarm
delay: the startup alarm delay and loop alarm delay. Startup alarm delay
(which you can set in the Setup Global Parameters main menu) delays
process alarms (but not failed sensor alarms) for all loops for a specified
time after the controller powers up.
The loop alarm delay, in contrast, is set separately for each loop. It
delays failed sensor and process alarms until the alarm condition has
been continuously present for longer than the alarm delay time. (Failed
sensor alarms are not subject to the startup alarm delay, but they are
affected by the loop's alarm delay during the startup alarm delay
period.)
LOOP
PROCESS
UNITS
04 ALARM DELAY ?
0 SECONDS
ALARM SETPOINT
STATUS
OUT%
Selectable range: 0-255 seconds.
MLS User’s Guide 95
Setup
Manual I/O Test
Press Yes at this prompt to see menus which can help you test the digital
inputs, digital outputs and the MLS' keypad.
LOOP
PROCESS
UNITS
MANUAL I/O
TEST ?
ALARM SETPOINT
STATUS
OUT%
The next figure shows the I/O Test menu tree. Notice the default values
inside the boxes.
Manual I/O Test?
Test digital inputs?
HHHHHHHH
Test keypad?
Quit = "NO" + "NO"
Test digital output?
one in use
Toggle digital output?
Off
96 MLS User’s Guide
Setup
Digital Input Testing
Use this menu to view the logic state of the 8 digital inputs as H (High-the input is at 5 volts or is not connected) or L (Low--the input is at zero
volts). The menu displays inputs 1 to 8 from left to right. Since inputs
are pulled High when they are not connected, test an input by shorting it
to controller common and making sure this menu shows the correct state
for that input.
LOOP
PROCESS
UNITS
DIGITAL INPUTS
HHHHHHHH
ALARM SETPOINT
STATUS
OUT%
Using This Menu
• Short the digital input you are testing to controller common. When
you do that, the input's state should change to L.
• Press Yes or No to advance to the next menu.
• Press Back to return to the Manual I/O test main menu.
Keypad Test
Use this menu to test the keypad.
LOOP
PROCESS
UNITS
KEYPAD TEST
QUIT = "NO" + "NO"
ALARM SETPOINT
STATUS
OUT%
Using This Menu
• Press any key to test the keypad. The MLS will display the name of
the key you have pressed.
• Press No twice to advance to the next menu.
Test Digital Output
Use this menu to select one of the digital alarm outputs to test in the next
menu.
LOOP
PROCESS
UNITS
TEST DIGITAL
OUTPUT ? 34
ALARM SETPOINT
STATUS
OUT%
MLS User’s Guide 97
Setup
Toggle Digital Output
Use this menu to manually toggle a digital output On or Off to test it.
(You select the output to test in the previous menu.) On may be Low or
High depending on the digital output polarity you set in the Output
Polarity menu. (All outputs are set to Off when you exit Manual I/O Test
menu.)
LOOP
PROCESS
UNITS
DIGITAL OUTPUT
NUMBER 17? OFF
ALARM SETPOINT
STATUS
OUT%
Selectable values: On or Off.
98 MLS User’s Guide
Tuning and Control
Tuning and Control
Introduction
This chapter explains PID control and supplies some starting PID values
and tuning instructions, so that you can use control parameters
appropriate for your system. If you would like more information on PID
control, consult the ANAFAZE Practical Guide to PID.
The control mode dictates how the controller responds to an input
signal. The control mode is different from the type of control output
signal (like analog or pulsed DC voltage). There are several control
modes available: On/Off, Proportional (P), Proportional and Integral
(PI), Proportional with Derivative, and Proportional with Integral and
Derivative (PID). P, PI, or PID control are necessary when process
variable (PV) cycling is unacceptable or if the process or setpoint (SP) is
variable.
NOTE
For any of these control modes to function, the
loop must be in Automatic mode.
Control Modes
The next sections explain the different modes you can use to control a
loop.
On/Off Control
On/Off control is the simplest way to control a process; a controller
using On/Off control turns an output on or off when the process variable
reaches a certain limit above or below the desired setpoint. You can
adjust this limit, since ANAFAZE’s controllers use an adjustable spread.
For example, if your setpoint is 1000 ºF, and your limit (spread) is 20
ºF, the output switches On when the process variable goes below 980 ºF
and Off when the process goes above 1000 ºF.
MLS User’s Guide 99
Tuning and Control
The next diagram shows a process under On/Off control.
Proportional Control
A process using On/Off control frequently cycles around the setpoint.
When process variable cycling is unacceptable or the process or setpoint
are variable, use proportional control. Proportional control, or Gain,
eliminates cycling by increasing or decreasing the output proportional to
the process variable's distance from the setpoint.
The limits of proportional control are defined by the Proportional Band
(PB); outside this band of control, the output is either 100% or 0%. For
example--using the same values from the example above and a PB of
20º---the output is:
• 50% when the process variable is 990 ºF
• 75% when the process variable is 985 ºF
• 100% when the process variable is 980 ºF or below.
However, a process which uses only Proportional control may settle at a
point above or below the setpoint; it may never reach the setpoint at all.
This behavior is known as “offset” or “droop”.
This diagram shows a process under proportional control only.
100 MLS User’s Guide
Tuning and Control
Proportional and Integral Control
For Proportional and Integral control, use the Integral term, or Reset,
with Proportional control. The Integral term corrects for offset by
repeating the Proportional band's error correction until there is no error.
For example, if a process tends to settle about 5 ºF below the setpoint,
use Integral control to bring it to the desired setting.
The next diagram shows a process under proportional and integral
control.
Proportional, Integral and Derivative Control
For an improved level of control, use Derivative control with
Proportional or Proportional and Integral control. Derivative control,
also called the Rate function, corrects for overshoot by anticipating the
behavior of the process variable and adjusting the output appropriately.
For example, if the process variable is rapidly approaching the setpoint,
Derivative control reduces the output, anticipating that the process
variable will reach setpoint. Use it to eliminate the process variable
overshoot common to PI control.
This figure shows a process under full PID (Proportional, Integral, and
Derivative) control.
MLS User’s Guide 101
Tuning and Control
Digital Output Control Forms
The next section explains different modes for control outputs.
On/Off
On/Off output is very simple: it turns the output on or off according to
the control signal of the On/Off control.
Time Proportioning (TP)
Time Proportioning attempts to digitally simulate an analog output
percentage by turning the output On or Off for each time step, so that
the cumulative average of the output is the desired setting. You must
enter a cycle time for TP outputs. The cycle time is the time over which
the output is proportioned, and it can be any value from 1 to 255
seconds. For example, if the output is 30% and the Cycle Time is 10
seconds, then the output will be on for 3 seconds and off for 7. The
figure below shows typical TP and DZC graphs.
Distributed Zero Crossing (DZC)
DZC output is essentially a Time Proportioning output. However, for
each AC line cycle the controller decides whether the power should be
On or Off. There is no Cycle Time since the decision is made for each
line cycle. Since the time period for 60 Hz power is 16.6 ms, the
switching interval is very short and the power is applied uniformly.
Switching is done only at the zero crossing of the AC line, which helps
reduce electrical “noise”.
DZC output is primarily used for very fast acting electrical heating loads
using Solid State Relays (SSRs). For instance, the open air heater coil is
an example of a fast acting load. Do not use DZC output for
electromechanical relays.
The combination of DZC output and a solid state relay can
inexpensively approach the effect of analog phase angle fired control.
Analog Outputs
The Serial DAC is an optional analog output module for the CLS. It lets
the controller output precision analog voltages or currents--typically for
precision open-loop control, motor or belt speed control, or phase angle
fired control. To use it, set the output type for the appropriate loop to
SDAC.
102 MLS User’s Guide
Tuning and Control
ANAFAZE also offers the DAC, another optional analog output module
for the MLS. It converts two DZC outputs to two 4-20 mA current
outputs.
Output Digital Filter
The output filter digitally filters the PID control output signal. It has a
range of 0-255 levels, which gives a time constant of 0-127.5 seconds.
Use the output filter if you need to filter out erratic output swings due to
extremely sensitive input signals, like a turbine flow signal or an open
air thermocouple in a dry air gas oven.
The output filter can also enhance PID control. Some processes are very
sensitive and require a high PB, so normal control methods are
ineffective. You can use a smaller PB- and get better control- if you use
the digital filter to reduce the high and low process output swings.
You can also use the filter to reduce output noise when a large derivative
is necessary, or to make badly tuned PID loops and poorly designed
processes behave properly.
Reverse and Direct Action
Reverse action is an output control action in which an increase in the
process variable causes a decrease in the output. Direct action is an
output control action in which an increase in the process variable causes
an increase in the output. Heating applications normally use reverse
action and cooling applications usually use direct action.
MLS User’s Guide 103
Tuning and Control
Setting Up and Tuning PID Loops
To start your process after installation, tune the control loops and set
them to automatic control. If the loop is already in automatic control
mode and controlling the process, set the loop to manual control. Then
you can tune it without upsetting the process. However, if you don’t
mind minor process fluctuations, you can tune the loop in automatic
control mode.
NOTE
Remember that tuning is a slow process. After you
change a PID parameter, allow time (20 minutes
for most processes) before you make another
change.
Proportional Band (PB) Settings
This table shows PB settings for several setpoints.
Temperature
Setpoint
PB
Temperature
Setpoint
PB
Temperature
Setpoint
PB
-100 to 99
20
1100 to 1199
75
2200 to 2299
135
100 to 199
20
1200 to 1299
80
2300 to 2399
140
200 to 299
30
1300 to 1399
85
2400 to 2499
145
300 to 399
35
1400 to 1499
90
2500 to 2599
150
400 to 499
40
1500 to 1599
95
2600 to 2699
155
500 to 599
45
1600 to 1699
100
2700 to 2799
160
600 to 699
50
1700 to 1799
105
2800 to 2899
165
700 to 799
55
1800 to 1899
110
2900 to 2999
170
800 to 899
60
1900 to 1999
120
3000 to 3099
175
900 to 999
65
2000 to 2099
125
3100 to 3199
180
1000 to 1099
70
2100 to 2199
130
3200 to 3299
185
Setting the PB: a General Rule
Set the PB to 10% of the setpoint below 1000º and 5% of the setpoint
above 1000º. This setting is useful as a starting value.
104 MLS User’s Guide
Tuning and Control
Integral Term (TI) Settings
This table shows Integral vs. Reset repeats per minute.
TI
(secs./repeat)
Reset
(repeats/min)
TI
(secs./repeat0
Reset
(repeats/min)
30
2.0
210
0.28
45
1.3
240
.25
60
1.0
270
.22
90
.66
300
.20
120
.50
400
.15
150
.40
500
.12
180
.33
600
.10
Setting the TI: A General Rule
Use 60, 120, 180, or 240 as a starting value for the TI.
Derivative Term (TD) Settings
This table shows Derivative term (TD) vs. Rate Minutes (RM);
Rate=TD/60.
TD
(secs./repeat)
Rate
(repeats/min)
TD
(secs./repeat)
Rate
(repeats/min)
5
.08
35
.58
10
.16
40
.66
15
.25
45
.75
20
.33
50
.83
25
.41
55
.91
30
.50
60
1.0
Setting the TD: A General Rule
Set the TD to 15% of TI as a starting value.
MLS User’s Guide 105
Tuning and Control
General PID Constants
This section gives general PID constants.
Proportional Band Only (P)
Set the PB to 7% of the setpoint
Example: Setpoint = 450, set the Proportional Band to 31.
Proportional with Integral (PI)
Set the PB to 10% of setpoint.
Example: Setpoint = 450, set PB to 45.
Set TI to 60.
Set TD to Off.
Set the Output Filter to 2.
PI with Derivative (PID)
Set the PB to 10% of the SP.
Set the TI to 60.
Set the TD to 15% of the TI. Example: TI = 60, so TD = 9).
Set the Output Filter to 2.
PB
TI
TD
FIL
OUTPUT
CT
Action
Electric heat with solid state
relays
50
60
15
4
TP
3
Reverse
Electric heat with mechanical relays
50
60
15
6
TP
20
Reverse
Gas heat with motorized
values
60
120
25
8
DZC/DAC
NA
Reverse
Gas heat with motorized values (SP > 1200° F)
100
240
40
8
DZC/DAC
NA
Reverse
Extruders with cooling, Heat
with SSRs
50
300
90
8
TP
3
Reverse
Spread set to zero, cool with
solenoid valve
10
OFF
OFF
4
TP
20
Direct
Cool with fans
10
OFF
OFF
4
TP
60
Direct
Electric heat with open heat
coils
30
20
OFF
4
DZC
NA
Reverse
Electric heat with SCR controllers
60
60
15
4
DZC/DAC
NA
Reverse
106 MLS User’s Guide
Tuning and Control
MLS User’s Guide 107
Tuning and Control
108 MLS User’s Guide
Troubleshooting
Troubleshooting
The next few sections describe general troubleshooting for the MLS.
Later sections describe specific procedures, like checking an input,
changing the EPROM, and testing the controller.
First, Check your Installation
The controller is only part of your control system. Often, what appears
to be a problem with the MLS is really a problem with other equipment,
so check these things first:
• Controller is installed correctly. (See Chapter 2: Installation for
help.)
• Inputs, like thermocouples and RTDs, are installed correctly with
correct scaling resistors, and working correctly.
Second, Replace Unit
WARNING
Check the installation before you replace the controller! If the controller wasn't installed correctly,
for instance, if you have shorted sensor inputs to
high voltage lines or a transformer is shorted out,
and you replace the MLS with a spare unit, the
spare unit will break, and you'll need to send both
units to ANAFAZE for repair.
If you are certain that the controller is installed correctly, you can try
replacing the MLS with a spare controller -- one module at a time. If the
spare unit works correctly, then the problem is specific to the MLS you
replaced.
If you need to update the MLS Erasable Programmable Read-Only
Memory (EPROM), please refer to the third section, Changing the
EPROM.
Manual Controller Reset
If the instructions in this chapter tell you to perform a "manual
controller reset" (also called a "No Key Reset"), follow these
instructions:
• Disconnect power to the unit.
• Press and hold the No key on the MLS front panel. Reconnect power
to the unit.
MLS User’s Guide 109
Troubleshooting
WARNING
A manual controller reset clears the MLS memory
and resets its parameters to their default values. If
you reset a stand-alone system, you cannot recover
your original parameters. If you have a computer
supervised system, ANASOFT stores a copy of
your parameters.
Do not attempt to repair the MLS yourself. There
are no user-repairable components in the MLS. If
the troubleshooting procedures in this chapter do
not solve your system's problems, you will need to
return the unit to ANAFAZE for testing and
repair, see Returning the Unit to ANAFAZE below.
Returning your Unit to ANAFAZE
If you need to return the MLS to ANAFAZE, please call ANAFAZE for
a Returned Materials Authorization (RMA) number. The RMA number
helps us track your equipment and return it to you as soon as possible.
Try to figure out if the problem is in the MLS-PM or the MLS-AIM, and
send only that part for repair.
Troubleshooting Stand-Alone Systems
The MLS is self contained, so there are very few things you can test if it
is not functioning properly. However, the MLS is only part of a control
system; check other parts of the system, like thermocouples, before you
assume that the unit is broken.
You may assume that there is a problem if:
• The LEDs on the Analog Input Module (AIM) are not blinking.
• The MLS Processor Module's LCD screen is not lit.
• The LCD screen does not display graphics or characters.
The rest of this section describes common problems and solutions for
stand-alone systems.
MLS-PM Has No Power
If you supply power to the MLS-PM and the LCD screen does not light
up, check the power supply and its connections. Follow the instructions
in the Power Wiring and Controller Test section of the Installation
chapter.
110 MLS User’s Guide
Troubleshooting
Keys Don't Respond
If the MLS seems to function perfectly, but the Man/Auto, Chng SP,
Alarm Ack, and Ramp/Soak keys do not respond when you press
them, then you are probably locked out of the system. Ask your
supervisor to unlock the keyboard according to the instructions in the
Setup Global Parameters section.
Controller Message: AIM Comm Failure
If you power up the MLS-PM and the message AIM COMM FAIL
appears, or if the LED on the AIM is not blinking, check the following:
• Make sure power supply connections are correct (see the Power Wiring and Controller Test section of the Installation chapter).
• Make sure the AIM Communications cable is plugged into the AIM
and the connector labeled "TO AIM" on the MLS-PM.
If the AIM COMM FAIL message still appears, perform a manual
controller reset. If the MLS still does not power up with the Bar Graph
Display, return the unit to ANAFAZE for repair.
Checking Analog Inputs
If the number of inputs recognized by the MLS-PM does not agree with
the number of inputs in the MLS-AIM, perform a manual controller
reset with the AIM connected to the processor module. If the numbers
still don't agree, check the following:
Make sure the input wires are properly connected. Every input on
the MLS-AIM has three screw terminals: positive, negative, and
auxiliary. All T/C, milliamp, and voltage inputs connect to the positive
and negative terminals. RTD inputs connect to all three terminals.
Check for high common mode voltage. It is not uncommon for heaters
to leak into the T/C wires. Use an AC Voltmeter for testing.
If the inputs are not reading properly, make sure you have selected
the correct input type from the Setup menus (see Chapter 4: Setup).
Checking the Operation of an Input
• Disconnect the sensor wiring.
• Set the input sensor to type J T/C from the Setup menus.
• Place a short across the input.
The process variable should indicate ambient temperature. If it does not,
call ANAFAZE for an RMA number and return the unit for repair.
If the process variable indicates ambient temperature, then the MLS is
working correctly and the problem lies in the sensor or sensor wiring.
You can test T/C or RTD sensors with a Multimeter.
MLS User’s Guide 111
Troubleshooting
• To check thermocouple inputs, unplug the AIM module and measure
between the A+ and A- terminals of the AIM-TB. Thermocouple
inputs should not read above 200 ohms.
• To check RTD inputs, unplug the AIM module and measure between
the A+ and A- terminals. Then measure between the A+ and A
COM terminals of the AIM-TB. RTD inputs should read between
20 and 250 ohms. Both readings should be the same.
Make sure other inputs operate within the AIM's full scale voltage (60
mVdc). If they do not, install scaling resistors on the MLS-AIM-TB (see
Chapter 2: Installation).
Checking PID Control Outputs
To check control outputs:
• Set the loop you want to check to Manual mode.
• Set the output power percentage to the desired level.
• Set the output type to On/Off or TP (see Chapter 4: Setup).
Testing Control Output Devices
To test a control output device like an SSR, use a digital multimeter set
to DC voltage. Connect the positive lead of the multimeter to the MLS
+5V and the negative lead to the control output. The multimeter should
read 0 Vdc when the output is 0% and +5 Vdc when the output is 100%.
If the control output is not connected to an output device like an SSR,
connect an LED in series with a 1K resistor from +5 V to the output.
(Tie the anode of the LED to +5V.) The LED should be Off when the
output is 0% and On when the output is 100%.
Checking Digital I/O
You can check digital inputs and outputs from the Setup menus (see
Chapter 4: Setup) or you can use the techniques described above for
PID control outputs.
112 MLS User’s Guide
Troubleshooting
Checking Computer Supervised Systems
These four elements must work properly in a computer-supervised
system:
• The MLS.
• The computer and its RS-232 or RS-485 serial interface.
• The RS-232 or RS-485 communication lines.
• The computer software.
For MLS troubleshooting, disconnect the communications line from the
computer and follow the troubleshooting steps in the first section of this
chapter. The next few sections explain troubleshooting for the other
elements of computer supervised systems.
Computer Problems
If you suspect computer problems, run ANASOFT in Edit mode to find
out if the computer works correctly. (See the ANASOFT User's Guide
for a description of correct operation.)
• If ANASOFT tells you that your computer is not functioning, contact
your computer service representative.
• Check your ANAINSTL program to make sure that ANASOFT and
the MLS are set for the same serial communications port. ANASOFT can use either COM1 or COM2.
• Make sure that you have set the same error checking method--either
BCC or CRC--in ANASOFT and in the processor module.
• Check that the communications baud rate is also set to the same
value--either 2400 or 9600--in ANASOFT and in the processor
module.
• Make sure you are using DOS 5.0 or a later version of DOS.
Serial Interface Problems
Set the serial interface according to the manufacturer's instructions. To
test an RS-232 interface, buy an RS-232 troubleshooter from Radio
Shack. Attach the troubleshooter between the MLS and the computer.
When ANASOFT sends data to the MLS, the troubleshooter's TX LED
should blink. When it receives data from the MLS, the RX LED should
blink.
MLS User’s Guide 113
Troubleshooting
If you use the Black Box RS-485 interface, make sure you have set it up
correctly. (See the Communications section in Chapter 2 for RS-485
setup instructions.) The LEDs on the unit should blink, but should not
stay lit. For either type of interface, you can connect an oscilloscope to
the transmit or receive line to see whether data is being sent or received.
If the serial interface does not function, contact your computer service
representative.
Communications Problems
If you are experiencing communications problems, check the
communications interface, cables, and connections.
NOTE
Most communications problems are due to incorre c t w i r i n g o r i m p ro p e r c o m m u n i c a t i o n s
parameters. Therefore, check the wiring and commu nic at io n s pa ra m ete rs b ef ore y ou che ck
anything else.
If your system has multiple MLS or other control units, you must use
RS-485 communications. Therefore, the internal RS-232/RS-485
selection jumper must be set to the correct position.
From the setup menus, make sure that the communications parameters
(address, error checking and baud rate) are set correctly for each MLS in
your system. Every controller must have a separate address, starting
with 1 and increasing by 1 for each controller. After you assign the
controller addresses, you must configure ANAINSTL with the same
parameters.
In multiple controller systems, ANASOFT indicates which controllers
are communicating and which are not. If you power down a controller in
a multiple-controller system, ANASOFT should indicate a COMM
FAILURE in that unit. Disable communications to that unit until you
power it up again.
Ground Loops
During installation, sometimes the MLS-PM common wire is tied to
earth ground, and the computer's RS-232 common wire is tied to earth
ground. This arrangement creates a ground loop which may affect
communications and other MLS functions. To avoid ground loops,
either use an optically isolated communications adapter or disconnect
the MLS from earth ground and tie an 0.1 microfarad capacitor from
MLS DC common to earth ground.
114 MLS User’s Guide
Troubleshooting
Software Problems
This section gives some solutions for software problems.
User-Written Software
If you don't want to use ANASOFT as your software interface to the
MLS, you are responsible for the correct operation of the software you
buy or write. You can request the ANAFAZE Communications
Specification if you want to write your own software. ANAFAZE will
answer any technical questions that arise during your software
development process, but ANAFAZE does not otherwise support user
software in any way.
If you write your own software, first write a routine that sends and
receives display commands to and from the MLS. The protocol includes
all characters, so the display should show the hexadecimal values of the
data sent in both directions. If you have problems with the software you
write, you can use this program to test your communications.
ANASOFT
If ANASOFT is not working, check these things first:
• ANAINSTL (the ANASOFT installation program) has the correct path for the program and data files.
• All the necessary files exist in the directory specified by the path.
• Your computer has enough memory. ANASOFT requires up to
640K of free memory to run. To maximize the amount of free memory available, use a memory manager (like HIMEM from DOS
5.0).
• Your computer is not running memory-resident programs.
Check your AUTOEXEC.BAT file to make sure that no memory
resident programs automatically run on startup; they may interfere
with ANASOFT.
• The software key is properly installed on the printer port. It
should plug into the printer port with the female end toward the
computer and the male end toward the printer. Do not remove the
screws on the software key to connect it.
If, after you check these things, ANASOFT still does not work correctly,
consult the ANASOFT User's Guide for more troubleshooting
information.
MLS User’s Guide 115
Troubleshooting
Changing the EPROM
Changing the EPROM involves minor mechanical disassembly and
reassembly of the controller, but you don't need any soldering or
electrical expertise. You'll need a Phillips head screwdriver and a small
flathead screwdriver.
NOTE
If you change the EPROM, you must perform a
manual controller reset for the EPROM change to
take effect. A manual controller reset changes all
controller parameters back to their default values,
so you must reenter the desired values from ANASOFT or from the controller's front panel after
you change the EPROM.
1. Power down the controller. Be sure to take antistatic precautions.
2. Remove the two or four screws from the sides of the controller front
panel and remove the two screws from the top of the case, as shown
below.
3. Remove the electronics assembly from the case, as shown below.
4. Unscrew the four screws at the corners of the top board and carefully
unplug this board to access the bottom board (processor board). The
next figure shows the screws to remove:
116 MLS User’s Guide
Troubleshooting
5. Locate the EPROM on the circuit board. The EPROM is a 28-pin
socketed chip which may have an ANAFAZE label on top of it. If
there is no label, a small window will be visible in the middle of the
top of the chip.
Do not confuse the EPROM with the RAM; the RAM also has 28
pins, but it is in a high-profile socket, and it does not have a label or a
window. (The component designation U2 is printed on the processor
board next to the EPROM socket.)
The next figure shows the EPROM and the RAM chip..
E
P
R
O
M
R
A
M
6. Remove the existing EPROM from its socket by prying it out with a
small flathead screwdriver, as shown below.
7. Carefully bend the legs of the new EPROM against a flat surface until
they line up with the holes in the EPROM socket.
8. Carefully insert the new EPROM into the EPROM socket. Make sure
that the chip is oriented so that its notch faces the same way as the
part outline on the board.
9. Reverse steps 2 through 4 to reassemble the unit.
10. Perform a manual controller reset. The reset reinitializes the battery
backed RAM. You must perform a manual controller reset for the unit
to operate properly.
MLS User’s Guide 117
Troubleshooting
118 MLS User’s Guide
Linear Scaling Examples
Linear Scaling Examples
Example 1: Configuring a Pressure Sensor
You’re using a pressure sensor that generates a 4-20 milliamp signal.
The sensor generates 4 milliamps at 0.0 PSI and 20 mA at 50.0 PSI.
Setup
You connect the sensor to a loop input set up with a resistor scaling
network to produce 60 millivolts at 20 mA. (See the Inputs section of
Chapter 2: Installation for more information on scaling networks.)
The sensor measures PSI in tenths, so the appropriate display format is 999.9 to +3000.0.
This table shows the input readings.
PV
Displayed
Sensor Input
Reading (%FS)
50.0 PSI
20
100%
0.0 PSI
4
100%x(4ma/20 ma) = 20%
Based on these input readings, use these scaling values:
Parameter
Low Value
High Value
Process Value (PV)
0.0 PSI
50.0 PSI
Input Reading (RDG)
20.0
100.0
MLS User’s Guide 119
Linear Scaling
Example 2: Configuring a Flow Sensor
You connect a flow sensor to the MLS to measure the flow in a pipe.
The sensor generates a 0-5V signal. The sensor's output depends on its
installation. Measurements of the flow in the pipe indicate that the
sensor generates 0.5 volts at three gallons per minute (GPM) and 4.75
volts at 65 GPM. The calibration instruments are precise to +1 gallon
per minute.
Setup
The sensor is connected to a loop input set up with a resistor voltage
divider network to produce 60 millivolts at 5 volts. (See the Inputs
section of the Installation chapter for information on scaling networks.)
The calibrating instrument is precise to ñ1 gallon per minute, so the
appropriate display format is -999 to +3000.
This table shows the input readings.
PV
Displayed
Sensor Input
Reading (%FS)
65 GPM
4.75
(4.75V / 5.00V) x 100%=95%
3 GPM
0.5
(0.5V / 5.00V) x 100%=10%
Based on these input readings, use these scaling values:
Parameter
120 MLS User’s Guide
Low Value
High Value
Process Value (PV)
3 GPM
65 GPM
Input Reading (RDG)
10.0
95.0
Glossary
A
AC
See Alternating Current.
AC Line Frequency
The frequency of the AC power line measured in
Hertz (Hz), usually 50 or 60 Hz.
Accuracy
Closeness between the value indicated by a measuring instrument and a physical constant or
known standards.
Action
The response of an output when the process variable is changed. See also Direct action, Reverse
action.
Address
A numerical identifier for a controller when used
in computer communications.
Alarm
A signal that indicates that the process has
exceeded or fallen below a certain range around
the setpoint. For example, an alarm may indicate
that a process is too hot or too cold. See also:
Deviation Alarm
Failed Sensor Alarm
Global Alarm
High Deviation Alarm
High Process Alarm
Loop Alarm
Low Deviation Alarm
Low Process Alarm
Alarm Delay
The lag time before an alarm is activated.
Alternating Current (AC)
An electric current that reverses at regular intervals, and alternates positive and negative values.
surrounds the components of a thermal system.
American Wire Gauge (AWG)
A standard of the dimensional characteristics of
wire used to conduct electrical current or signals.
AWG is identical to the Brown and Sharpe
(B&S) wire gauge.
Ammeter
An instrument that measures the magnitude of an
electric current.
Ampere (Amp)
A unit that defines the rate of flow of electricity
(current) in the circuit. Units are one coulomb
(6.25 x 1018 electrons) per second.
Analog Output
A continuously variable signal that is used to represent a value, such as the process value or setpoint value. Typical hardware configurations are
0-20mA, 4-20mA or 0-5 Vdc.
Automatic Mode
A feature that allows the controller to set PID
control outputs in response to the Process Variable (PV) and the setpoint.
Autotune
A feature that automatically sets temperature
control PID values to match a particular thermal
system.
B
Bandwidth
A symmetrical region above and below the setpoint in which proportional control occurs.
Baud Rate
The rate of information transfer in serial communications, measured in bits per second.
Ambient Temperature
The temperature of the air or other medium that
121
Glossary
MLS User’s Guide
Block Check Character (BCC)
A serial communications error checking method.
An acceptable method for most applications,
BCC is the default method. See CRC.
Bumpless Transfer
A smooth transition from Auto (closed loop) to
Manual (open loop) operation. The control output
does not change during the transfer.
C
Calibration
The comparison of a measuring device (an
unknown) against an equal or better standard.
Celsius (Centigrade)
Formerly known as Centigrade. A temperature
scale in which water freezes at 0°C and boils at
100°C at standard atmospheric pressure. The formula for conversion to the Fahrenheit scale is:
°F=(1.8x°C)+32.
Central Processing Unit (CPU)
The unit of a computing system that includes the
circuits controlling the interpretation of instructions and their execution.
Circuit
Any closed path for electrical current. A configuration of electrically or electromagnetically-connected components or devices.
Closed Loop
A control system that uses a sensor to measure a
process variable and makes decisions based on
that feedback.
Cold Junction
Connection point between thermocouple metals
and the electronic instrument.
See Baud Rate.
Control Action
The response of the PID control output relative to
the error between the process variable and the
setpoint. For reverse action (usually heating), as
the process decreases below the setpoint the output increases. For direct action (usually cooling),
as the process increases above the setpoint, the
output increases.
Control Mode
The type of action that a controller uses. For
example, On/Off, time proportioning, PID, Automatic or manual, and combinations of these.
Current
The rate of flow of electricity. The unit of measure is the ampere (A).
1 ampere = 1 coulomb per second.
Cycle Time
The time required for a controller to complete
one on-off-on cycle. It is usually expressed in
seconds.
Cyclic Redundancy Check (CRC)
An error checking method in communications. It
provides a high level of data security but is more
difficult to implement than Block Check Character (BCC).
See Block Check Character.
D
Data Logging
A method of recording a process variable over a
period of time. Used to review process performance.
Common Mode Rejection Ratio
The ability of an instrument to reject electrical
noise, with relation to ground, from a common
voltage. Usually expressed in decibels (dB).
Communications
The use of digital computer messages to link
components.
See Serial Communications.
122
Deadband
The range through which a variation of the input
produces no noticeable change in the output. In
the deadband, specific conditions can be placed
on control output actions. Operators select the
MLS User’s Guide
Glossary
deadband. It is usually above the heating proportional band and below the cooling proportional
band.
Default Parameters
The programmed instructions that are permanently stored in the microprocessor software.
Derivative Control (D)
The last term in the PID algorithm. Action that
anticipated the rate of change of the process, and
compensates to minimize overshoot and undershoot. Derivative control is an instantaneous
change of the control output in the same direction
as the proportional error. This is caused by a
change in the process variable (PV) that
decreases over the time of the derivative (TD).
The TD is in units of seconds.
Deutsche Industrial Norms (DIN)
A set of technical, scientific and dimensional
standards developed in Germany. Many DIN
standards have worldwide recognition.
Deviation Alarm
Warns that a process has exceeded or fallen
below a certain range around the setpoint.
Digital to Analog Converter (DAC)
A device that converts a numerical input signal to
a signal that is proportional to the input in some
way.
Direct Action
An output control action in which an increase in
the process variable, causes an increase in the
output. Cooling applications usually use direct
action.
A metal rod, usually copper, that provides an
electrical path to the earth, to prevent or reduce
the risk of electrical shock.
Electrical Noise
See Noise.
Electromagnetic Interference (EMI)
Electrical and magnetic noise imposed on a system. There are many possible causes, such as
switching ac power on inside the sine wave. EMI
can interfere with the operation of controls and
other devices.
Electrical-Mechanical Relays
See Relay, electromechanical.
Emissivity
The ratio of radiation emitted from a surface
compared to radiation emitted from a blackbody
at the same temperature.
Engineering Units
Selectable units of measure, such as degrees Celsius and Fahrenheit, pounds per square inch,
newtons per meter, gallons per minute, liters per
minute, cubic feet per minute or cubic meters per
minute.
EPROM
Erasable Programmable, Read-Only Memory
inside the controller.
Error
The difference between the correct or desired
value and the actual value.
Direct Current (DC)
An electric current that flows in one direction.
Distributed Zero Crossing (DZC)
A form of digital output control. Similar to burst
fire.
E
Earth Ground
123
Glossary
MLS User’s Guide
F
is cleared directly from a controller or through a
user interface.
Fahrenheit
The temperature scale that sets the freezing point
of water at 32ºF and its boiling point at 212ºF at
standard atmospheric pressure. The formula for
conversion to Celsius is: ºC=5/9 (ºF-32ºF).
Global Digital Outputs
A pre-selected digital output for each specific
alarm that alerts the operator to shut down critical
processes when an alarm condition occurs.
Failed Sensor Alarm
Warns that an input sensor no longer produces a
valid signal. For example, when there are thermocouple breaks, infrared problems or resistance
temperature detector (RTD) open or short failures.
Ground
An electrical line with the same electrical potential as the surrounding earth. Electrical systems
are usually grounded to protect people and equipment from shocks due to malfunctions. Also
referred to a "safety ground".
Filter
Filters are used to handle various electrical noise
problems.
H
Digital Filter (DF) — A filter that allows the
response of a system when inputs change unrealistically or too fast. Equivalent to a standard
resistor-capacitor (RC) filter
Digital Adaptive Filter — A filter that rejects
high frequency input signal noise (noise spikes).
Heat/Cool Output Filter — A filter that slows
the change in the response of the heat or cool output. The output responds to a step change by
going to approximately 2/3 its final value within
the numbers of scans that are set.
Frequency
The number of cycles over a specified period of
time, usually measured in cycles per second. Also
referred to as Hertz (Hz). The reciprocal is called
the period.
G
Gain
The amount of amplification used in an electrical
circuit. Gain can also refer to the Proportional (P)
mode of PID.
Hertz(Hz)
Frequency, measured in cycles per second.
High Deviation Alarm
Warns that the process is above setpoint, but
below the high process variable. It can be used as
either an alarm or control function.
High Power
(As defined by ANAFAZE) Any voltage above
24 VAC or Vdc and any current level above 50
mAac or mAdc.
High Process Alarm
A signal that is tied to a set maximum value that
can be used as either an alarm or control function.
High Process Variable (PV)
See Process Variable (PV).
High Reading
An input level that corresponds to the high process value. For linear inputs, the high reading is a
percentage of the full scale input range. For pulse
inputs, the high reading is expressed in cycles per
second (Hz).
I
Global Alarm
Alarm associated with a global digital output that
124
Infrared
A region of the electromagnetic spectrum with
wavelengths ranging from one to 1,000 microns.
These wavelengths are most suited for radiant
MLS User’s Guide
Glossary
heating and infrared (noncontact) temperature
sensing.
changes reflectance or transmittance when an
electrical field is applied to it.
Input
Process variable information that is supplied to
the instrument.
Load
The electrical demand of a process, expressed in
power (watts), current (amps), or resistance
(ohms). The item or substance that is to be heated
or cooled.
Input Scaling
The ability to scale input readings (readings in
percent of full scale) to the engineering units of
the process variable.
Input Type
The signal type that is connected to an input, such
as thermocouple, RTD, linear or process.
Integral Control (I)
Control action that automatically eliminates offset, or droop, between setpoint and actual process
temperature.
See Auto-reset.
J
Job
A set of operating conditions for a process that
can be stored and recalled in a controller’s memory. also called a Recipe.
Loop Alarm
Any alarm system that includes high and low process, deviation band, deadband, digital outputs,
and auxiliary control outputs.
Low Deviation Alarm
Warns that the process is below the setpoint, but
above the low process variable. It can be used as
either an alarm or control function.
Low Process Alarm
A signal that is tied to a set minimum value that
can be used as either an alarm or control function.
Low Reading
An input level corresponding to the low process
value. For linear inputs, the low reading is a percentage of the full scale input range. For pulse
inputs, the low reading is expressed in cycles per
second (Hz).
Junction
The point where two dissimilar metal conductors
join to forma thermocouple.
L
Lag
The delay between the output of a signal and the
response of the instrument to which the signal is
sent.
Linear Input
A process input that represents a straight line
function.
Linearity
The deviation in response from an expected or
theoretical straight line value for instruments and
transducers. also called Linearity Error.
Liquid Crystal Display (LCD)
A type of digital display made of a material that
M
Manual Mode
A selectable mode that has no automatic control
aspects. The operator sets output levels.
Manual Reset
See Reset.
Milliampere (mA)
One thousandth of an ampere.
N
No Key Reset
A method for resetting the controller's memory
(for instance, after an EPROM change).
Noise
Unwanted electrical signals that usually produce
signal interference in sensors and sensor circuits.
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Glossary
MLS User’s Guide
See Electromagnetic Interference.
Noise Suppression
The use of components to reduce electrical interference that is caused by making or breaking
electrical contact, or by inductors.
Non Linear
Through ANAFAZE software, the Non Linear
field sets the system to linear control, or to one of
two non linear control options. Input 0 for Linear,
1 or 2 for non linear.
O
Offset
The difference in temperature between the setpoint and the actual process temperature. Offset
is the error in the process variable that is typical
of proportional-only control.
On/Off Control
A method of control that turns the output full on
until setpoint is reached, and then off until the
process error exceeds the hysteresis.
Open Loop
A control system with no sensory feedback.
Operator Menus
The menus accessible from the front panel of a
controller. These menus allow operators to set or
change various control actions or features.
Optical Isolation
Two electronic networks that are connected
through an LED (Light Emitting Diode) and a
photoelectric receiver. There is no electrical continuity between the two networks.
Output
Control signal action in response to the difference
between setpoint and process variable.
Output Type
The form of PID control output, such as Time
Proportioning, Distributed Zero Crossing,
SDAC, or Analog. Also the description of the
electrical hardware that makes up the output.
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Overshoot
The amount by which a process variable exceeds
the setpoint before it stabilizes.
P
Panel Lock
A feature that prevents operation of the front
panel by unauthorized people.
PID
Proportional, Integral, Derivative. A control
mode with three functions:
Proportional action dampens the system
response, Integral corrects for droops, and Derivative prevents overshoot and undershoot.
Polarity
The electrical quality of having two opposite
poles, one positive and one negative. Polarity
determines the direction in which a current tends
to flow.
Process Variable
The parameter that is controlled or measured.
Typical examples are temperature, relative
humidity, pressure, flow, fluid level, events, etc.
The high process variable is the highest value of
the process range, expressed in engineering units.
The low process variable is the lowest value of
the process range.
Proportional (P)
Output effort proportional to the error from setpoint. For example, if the proportional band is
20º and the process is 10º below the setpoint, the
heat proportioned effort is 50%. The lower the
PB value, the higher the gain.
Proportional Band (PB)
A range in which the proportioning function of
the control is active. Expressed in units, degrees
or percent of span.
See PID.
Proportional Control
A control using only the P (proportional) value of
PID control.
Pulse Input
Digital pulse signals from devices, such as opti-
MLS User’s Guide
Glossary
cal encoders.
R
Ramp
A programmed increase in the temperature of a
setpoint system.
Range
The area between two limits in which a quantity
or value is measured. It is usually described in
terms of lower and upper limits.
Recipe
See Job.
Reflection Compensation Mode
A control feature that automatically corrects the
reading from a sensor.
Relay
A switching device.
Electromechanical Relay — A power switching
device that completes or interrupts a circuit by
physically moving electrical contacts into contact
with each other. Not recommended for PID control.
Solid State Relay (SSR) — A switching
device with no moving parts that completes or interrupts a circuit electrically.
Reset
Control action that automatically eliminates offset or droop between setpoint and actual process
temperature.
See also Integral.
Automatic Reset — The integral function of a
PI or PID temperature controller that adjusts the
process temperature to the setpoint after the system stabilizes. The inverse of integral.
Automatic Power Reset
ing limit controls that
— A feature in latch-
Resistance
Opposition to the flow of electric current, measured in ohms.
Resistance Temperature Detector (RTD)
A sensor that uses the resistance temperature
characteristic to measure temperature. There are
two basic types of RTDs: the wire RTD, which is
usually made of platinum, and the thermistor
which is made of a semiconductor material. The
wire RTD is a positive temperature coefficient
sensor only, while the thermistor can have either
a negative or positive temperature coefficient.
Reverse Action
An output control action in which an increase in
the process variable causes a decrease in the output. Heating applications usually use reverse
action.
RTD
See Resistance Temperature Detector.
S
Serial Communications
A method of transmitting information between
devices by sending all bits serially over a single
communication channel.
RS-232—An Electronics Industries of America
(EIA) standard for interface between data terminal equipment and data communications equipment for serial binary data interchange. This is
usually for communications over a short distance
(50 feet or less) and to a single device.
RS-485—An Electronics Industries of America
(EIA) standard for electrical characteristics of
generators and receivers for use in balanced digital multipoint systems. This is usually used to
communicate with multiple devices over a common cable or where distances over 50 feet are
required.
Setpoint (SP)
The desired value programmed into a controller.
For example, the temperature at which a system
is to be maintained.
Shield
A metallic foil or braided wire layer surrounding
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Glossary
MLS User’s Guide
conductors that is designed to prevent electrostatic or electromagnetic interference from external sources.
Signal
Any electrical transmittance that conveys information.
Solid State Relay (SSR)
See Relay, Solid State.
Span
The difference between the lower and upper limits of a range expressed in the same units as the
range.
Spread
In heat/cool applications, the +/- difference
between heat and cool. Also known as process
deadband.
See deadband.
Stability
The ability of a device to maintain a constant output with the application of a constant input.
T
T/C Extension Wire
A grade of wire used between the measuring
junction and the reference junction of a thermocouple. Extension wire and thermocouple wire
have similar properties, but extension wire is less
costly.
TD (Timed Derivative)
The derivative function.
Thermistor
A temperature-sensing device made of semiconductor material that exhibits a large change in
resistance for a small change in temperature.
Thermistors usually have negative temperature
coefficients, although they are also available with
positive temperature coefficients.
Thermocouple (T/C)
A temperature sensing device made by joining
two dissimilar metals. This junction produces an
electrical voltage in proportion to the difference
128
in temperature between the hot junction (sensing
junction) and the lead wire connection to the
instrument (cold junction).
TI (Timed Integral)
The Integral term.
Transmitter
A device that transmits temperature data from
either a thermocouple or RTD by way of a twowire loop. The loop has an external power supply.
The transmitter acts as a variable resistor with
respect to its input signal. Transmitters are desirable when long lead or extension wires produce
unacceptable signal degradation.
U
Upscale Break Protection
A form of break detection for burned-out thermocouples. Signals the operator that the thermocouple has burned out.
Undershoot
The amount by which a process variable falls
below the setpoint before it stabilizes.
MLS User’s Guide
Glossary
V
Volt (V)
The unit of measure for electrical potential, voltage or electromotive force (EMF).
See Voltage.
Voltage (V)
The difference in electrical potential between two
points in a circuit. It’s the push or pressure behind
current flow through a circuit. One volt (V) is the
difference in potential required to move one coulomb of charge between two points in a circuit,
consuming one joule of energy. In other words,
one volt (V) is equal to one ampere of current (I)
flowing through one ohm of resistance (R), or
V=IR.
Z
Zero Cross
Action that provides output switching only at or
near the zero-voltage crossing points of the ac
sine wave.
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Glossary
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MLS User’s Guide
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