2 F2-04AD-1, F2-04AD-1L 4-Channel Analog Current Input

2 F2-04AD-1, F2-04AD-1L 4-Channel Analog Current Input
F2-04AD-1,
F2-04AD-1L 4-Channel
Analog Current Input
In This Chapter. . . .
— Module Specifications
— Setting the Module Jumpers
— Connecting the Field Wiring
— Module Operation
— Writing the Control Program
2
2--2
F2-04AD-1, F2-04AD-1L 4-Channel Analog Current Input
F2--04AD--1, (L)
4-Ch. Current Input
Module Specifications
F2--04AD--1
The F2--04AD--1 analog Input module provides
several hardware features.
S On-board 250 ohm, 1/2 watt precision resistors
provide substantial over-current-protection for
4--20mA current loops.
S Analog inputs are optically isolated from the
PLC logic.
S The module has a removable terminal block so
the module can be easily removed or changed
without disconnecting the wiring.
S With a DL240/250--1/260 CPU, you can read
all four channels in one scan.
S On-board active analog filtering and RISC-like
microcontroller provide digital signal processing
to maintain precision analog measurements in
noisy environments.
F2-04AD-1
IN
ANALOG
4CH
F2--04AD--1
10--30VDC
5mA
0V
+24V
CH1-CH1+
CH2-CH2+
CH3-CH3+
CH4-CH4+
ANALOG IN
4--20mA
F2-04AD-1L
F2--04AD--1L (Obsolete)
NOTE: In 2009 the F2--04AD--1L was
discontinued. A re--designed F2--04AD--1 was
released at the same time which can be powered
by either 12 VDC or 24VDC input power supplies.
This new module is a direct replacement for prior
F2--04AD--1 and all F2--04AD--1L modules. The
new module is a single circuit board design and
the jumper link locations are different. See Setting
the Module Jumpers on page 2--5. Also, some
specifications were changed on page 2--3.
Otherwise, the re--designed module functions the
same as the prior designs.
IN
F2--04AD--1
18--26.4VDC
80mA
0V
+12V
CH1-CH1+
CH2-CH2+
CH3-CH3+
CH4-CH4+
ANALOG IN
4--20mA
DL205 Analog Manual 7th Ed. Rev. B 4/10
ANALOG
4CH
F2-04AD-1, F2-04AD-1L 4-Channel Analog Current Input
Input
Specifications
2--3
These tables provide specifications for both the F2--04AD--1 and F2--04AD--1L
Analog Input Modules (all specifications are the same for both modules except for the
input voltage requirements). Review these specifications to make sure the module
meets your application requirements.
4, single ended (one common)
Input Range
4 to 20 mA current
Resolution
12 bit (1 in 4096)
Step Response
4.9 ms (*4.0 ms) to 95% of full step change
Crosstalk
--80 dB, 1/2 count maximum
Active Low-pass Filtering
--3 dB at 120Hz (*80Hz), 2 poles (--12 dB per octave)
Input Impedance
250Ω 0.1%, ½W current input
Absolute Maximum Ratings
--40 mA to +40 mA,
mA current input
Converter type
Successive approximation
Linearity Error (End to End)
1 count (0.025%
(0 025% of full scale) maximum
Input Stability
1 count
Full Scale Calibration Error
(Offset error not included)
12 counts maximum,
maximum @ 20mA current input
Offset Calibration Error
7 counts maximum,
maximum @ 4mA current input
Maximum Inaccuracy
.5% @ 25C
25 C (77F)
(77 F)
.65% 0 to 60_C (32 to 140F)
Accuracy
y vs. Temperature
p
50 ppm/
ppm/_C
C maximum full scale calibration
(including maximum offset change)
Recommended Fuse (external)
0 032 A,
0.032
A Series 217 fast-acting,
fast-acting current inputs
One count in the specification table is equal to one least significant bit of the analog data value (1 in 4096).
PLC Update Rate
1 channel per scan maximum (DL230 CPU)
4 channels per scan maximum (DL240/250--1/260 CPU)
Digital Inputs
Input points required
12 binary data bits, 2 channel ID bits, 2 diagnostic bits
16 point (X) input module
Power Budget Requirement
100 mA (*50 mA) maximum,
maximum 5 VDC (supplied by base)
External Power Supply
5mA (*80mA) max., 10 (*18) to 30 VDC (F2-04AD-1)
90mA maximum, 10 to 15 VDC (F2-04AD-1L)
Operating Temperature
0 to 60_ C (32 to 140 F)
Storage Temperature
-20 to 70_ C (-4 to 158 F)
Relative Humidity
5 to 95% (non-condensing)
Environmental air
No corrosive gases permitted
Vibration
MIL STD 810C 514.2
Shock
MIL STD 810C 516.2
Noise Immunity
NEMA ICS3--304
* Values in parenthesis with an asterisk are for older modules with two circuit board design and date codes
0609F3 or previous. Values not in parenthesis are for single circuit board models with date code 0709G or above.
Analog Input
Configuration
Requirements
Appears as a 16-point discrete input module and can be installed in any slot of a DL205
system. The available power budget and discrete I/O points are the limiting factors.
Check the user manual for your particular model of CPU and I/O base for more
information regarding power budget and number of local, local expansion or remote
I/O points.
DL205 Analog Manual 7th Ed. Rev. B 4/10
F2--04AD--1, (L)
4-Ch. Current Input
Number of Channels
2--4
F2-04AD-1, F2-04AD-1L 4-Channel Analog Current Input
Special Placement
Requirements
(DL230 and
Remote I/O Bases)
Even though the module can be placed in any slot, it is important to examine the
configuration if you are using a DL230 CPU. As you can see in the section on writing
the program, you use V-memory locations to extract the analog data. If you place the
module so that the input points do not start on a V-memory boundary, the instructions
cannot access the data. This also applies when placing this module in a remote base
using a D2--RSSS in the CPU slot.
F2-04AD-1
F2--04AD--1, (L)
4-Ch. Current Input
Correct!
Slot 0
Slot 1
8pt
Input
8pt
Input
Slot 2
16pt
Input
16pt
Input
16pt
Output
X0
-X7
X10
-X17
X20
-X37
X40
-X57
Y0
-Y17
V40400
Data is correctly entered so input
points start on a V-memory boundary.
Slot 3
Slot 4
V40402
V40401
MSB
LSB
X
3
7
Incorrect
X
2
0
F2-04AD-1
Slot 0
Slot 1
Slot 2
Slot 3
8pt
Input
16pt
Input
16pt
Input
16pt
Input
Slot 4
16pt
Output
X0
-X7
X10
-X27
X30
-X47
X50
-X67
Y0
-Y17
Data is split over two locations, so instructions cannot access data from a DL230.
MSB
V40401
LSB
X X
3 2
0 7
X
3
7
X
2
0
MSB
V40400
LSB
X X
1 7
0
X
1
7
X
0
To use the V-memory references required for a DL230 CPU, the first input address
assigned to the module must be one of the following X locations. The table also shows
the V-memory addresses that correspond to these X locations.
X
X0
X20
X40
V
V40400 V40401 V40402 V40403 V40404 V40405 V40406 V40407
DL205 Analog Manual 7th Ed. Rev. B 4/10
X60
X100
X120
X140
X160
F2-04AD-1, F2-04AD-1L 4-Channel Analog Current Input
2--5
Setting the Module Jumpers
Selecting the
Number of
Channels
Jumper Location on Modules Having
Date Code 0609F3 and Previous
(Two Circuit Board Design)
+1
For example, to select all 4
channels (1 -- 4), leave both
jumpers installed. To select
channel 1, remove both jumpers.
Jumper Location on Modules Having
Date Code 0709G and Above
(Single Circuit Board Design)
+2
+1 +2
Jumper +1
These jumpers are located on the
motherboard, the one with the black
D-shell style backplane connector.
DL205 Analog Manual 7th Ed. Rev. B 4/10
F2--04AD--1, (L)
4-Ch. Current Input
There are two jumpers, labeled +1 and
+2, that are used to select the number of
channels that will be used. See the
figures below to find the jumpers on your
module. The module is set from the
factory for four channel operation.
Any unused channels are not
processed, so if you only select
channels 1 thru 3, channel 4 will not be
active. The following table shows how to
use the jumpers to select the number of
channels.
No. of Channels
+1
+2
1
No
No
1, 2
Yes
No
1, 2, 3
No
Yes
1, 2, 3, 4
Yes
Yes
2--6
F2-04AD-1, F2-04AD-1L 4-Channel Analog Current Input
Connecting the Field Wiring
F2--04AD--1, (L)
4-Ch. Current Input
Wiring Guidelines
User Power
Supply
Requirements
Your company may have guidelines for wiring and cable installation. If so, you
should check those before you begin the installation. Here are some general
things to consider:
S Use the shortest wiring route whenever possible.
S Use shielded wiring and ground the shield at the transmitter source. Do
not ground the shield at both the module and the source.
S Do not run the signal wiring next to large motors, high current switches, or
transformers. This may cause noise problems.
S Route the wiring through an approved cable housing to minimize the risk
of accidental damage. Check local and national codes to choose the
correct method for your application.
The module requires at least one field-side power supply. You may use the same or
separate power sources for the module supply and the current transmitter supply.
The F2-04AD-1 module requires 18--30VDC, at 80 mA. The DL205 bases have
built-in 24 VDC power supplies that provide up to 300mA of current. You may use
this with F2-04AD-1 modules instead of a separate supply if you are using only a
couple of analog modules.
It is desirable in some situations to power the transmitters separately in a location
remote from the PLC. This will work as long as the transmitter supply meets the voltage
and current requirements, and the transmitter’s minus (--) side and the module
supply’s minus (--) side are connected together.
WARNING: If you are using the 24 VDC base power supply, make sure you calculate
the power budget. Exceeding the power budget can cause unpredictable system
operation that can lead to a risk of personal injury or damage to equipment.
The DL205 base has a switching type power supply. As a result of switching noise, you
may notice 3--5 counts of instability in the analog input data if you use the base power
supply. If this is unacceptable, you should try one of the following:
1. Use a separate linear power supply.
2. Connect the 24VDC common to the frame ground, which is the screw
terminal marked “G” on the base.
By using these methods, the input stability is rated at 1 count.
The F2-04AD-1L module requires 10--15VDC, at 90 mA and must be powered by a
separate power supply.
DL205 Analog Manual 7th Ed. Rev. B 4/10
F2-04AD-1, F2-04AD-1L 4-Channel Analog Current Input
Current Loop
Transmitter
Impedance
2--7
Standard 4 to 20 mA transmitters and transducers can operate from a wide variety of
power supplies. Not all transmitters are alike and the manufacturers often specify a
minimum loop or load resistance that must be used with the transmitter.
The F2-04AD-1, (L) provides 250 ohm resistance for each channel. If your transmitter
requires a load resistance below 250 ohms, you do not have to make any adjustments.
However, if your transmitter requires a load resistance higher than 250 ohms, you
need to add a resistor in series with the module.
Consider the following example for a transmitter being operated from a 30 VDC supply
with a recommended load resistance of 750 ohms. Since the module has a 250 ohm
resistor, you need to add an additional resistor.
R ≥ 500
R -- resistor to add
Tr -- Transmitter Requirement
Mr -- Module resistance (internal 250 ohms)
Two-wire Transmitter
+
-DC Supply
+30V
0V
Module Channel 1
R
CH1+
CH1-0V
250 ohms
DL205 Analog Manual 7th Ed. Rev. B 4/10
F2--04AD--1, (L)
4-Ch. Current Input
R = Tr − Mr
R = 750 − 250
2--8
F2-04AD-1, F2-04AD-1L 4-Channel Analog Current Input
Wiring Diagram
The F2--04AD--1, (L) module has a removable connector to make wiring easier. Simply
squeeze the top and bottom retaining clips and gently pull the connector from the
module. Use the following diagram to connect the field wiring. The diagram shows
separate module and transmitter power supplies. If you desire to use only one
field-side supply, just combine the supplies’ positive (+) terminals into one node, and
remove the transmitter supply.
Module Supply
See NOTE 5
10--15 VDC
18--30 VDC
+
--
Internal
Module
Wiring
See NOTE 1
0 VDC See NOTE 5
+24 VDC
--
+
-CH1
4--wire
+
4--20mA
Transmitter
CH1--
CH2--
-CH4
2-wire
+
4--20mA
Transmitter
0V
F2--04AD--1
CH3--
Fuse
250 ohms
CH3+
CH4--
Fuse
10--30VDC
5mA
250 ohms
CH2+
--
CH3
2-wire
+
4--20mA
Transmitter
+5V
+15V
--15V
250 ohms
CH4+
Fuse
Analog Switch
-CH2
3--wire
+
4--20mA
Transmitter
250 ohms
ANALOG
4CH
CH1+
Fuse
+
IN
DC to DC
Converter
F2--04AD--1, (L)
4-Ch. Current Input
Typical User Wiring
A to D
Converter
0V
+24V
CH1-CH1+
CH2-CH2+
CH3-CH3+
CH4-CH4+
ANALOG IN
4--20mA
+
-18-30VDC
Supply
Transmitter Supply
OV
24 Volts Model Shown
NOTE 1: Shields should be grounded at the signal source.
NOTE 2: More than one external power supply can be used, provided all the power supply commons are connected.
NOTE 3: A Series 217, 0.032A fast-acting fuse is recommended for 4--20 mA current loops.
NOTE 4: If the power supply common of an external power supply is not connected to 0VDC on the module, then the
output of the external transmitter must be isolated. To avoid “ground loop” errors, recommended 4--20 mA
transmitter types are:
2 or 3 wire: Isolation between input signal and power supply.
4 wire:
Isolation between input signal, power supply, and 4--20mA output.
NOTE 5: Use 10--15VDC for F2-04AD-1L
Use 18--30VDC for F2-04AD-1
DL205 Analog Manual 7th Ed. Rev. B 4/10
F2-04AD-1, F2-04AD-1L 4-Channel Analog Current Input
2--9
Module Operation
Channel
Scanning
Sequence for a
DL230 CPU
(Multiplexing)
Scan
System With
DL230 CPU
Read Inputs
Execute Application Program
Read the data
Store data
Scan N
Channel 1
Scan N+1
Channel 2
Scan N+2
Channel 3
Scan N+3
Channel 4
Scan N+4
Channel 1
Write to Outputs
DL205 Analog Manual 7th Ed. Rev. B 4/10
F2--04AD--1, (L)
4-Ch. Current Input
Before you begin writing the control program, it is important to take a few minutes to
understand how the module processes and represents the analog signals.
The module can supply different amounts of data per scan, depending on the type
of CPU you are using. The DL230 can obtain one channel of data per CPU scan.
Since there are four channels, it can take up to four scans to get data for all
channels. Once all channels have been scanned the process starts over with
channel 1. Unused channels are not processed, so if you select only two channels,
then each channel will be updated every other scan. The multiplexing method can
also be used for the DL240/250--1 and DL260 CPUs.
2--10
F2-04AD-1, F2-04AD-1L 4-Channel Analog Current Input
Channel
Scanning
Sequence for a
DL240, DL250--1 or
or DL260 CPU
(Pointer Method)
If you are using a DL240/250--1/260 CPU , you can obtain all four channels of input
data in one scan. This is because the DL240/250--1/260 CPU supports special
V-memory locations that are used to manage the data transfer. This is discussed in
more detail in the section on Writing the Control Program.
Scan
System With
DL240/250--1/260
CPU
F2--04AD--1, (L)
4-Ch. Current Input
Read Inputs
Execute Application Program
Read the data
Store data
Scan N
Ch 1, 2, 3, 4
Scan N+1
Ch 1, 2, 3, 4
Scan N+2
Ch 1, 2, 3, 4
Scan N+3
Ch 1, 2, 3, 4
Scan N+4
Ch 1, 2, 3, 4
Write to Outputs
Analog Module
Updates
Even though the channel updates to the CPU are synchronous with the CPU scan,
the module asynchronously monitors the analog transmitter signal and converts
the signal to a 12-bit binary representation. This enables the module to
continuously provide accurate measurements without slowing down the discrete
control logic in the RLL program.
For the vast majority of applications, the values are updated much faster than the
signal changes. However, in some applications, the update time can be important.
The module takes approximately 4 milliseconds to sense 95% of the change in the
analog signal.
Note, this is not the amount of time required to convert the signal to a digital
representation. The conversion to the digital representation takes only a few
microseconds. Many manufacturers list the conversion time, but it is the settling
time of the filter that really determines the update time.
DL205 Analog Manual 7th Ed. Rev. B 4/10
2--11
F2-04AD-1, F2-04AD-1L 4-Channel Analog Current Input
Understanding
the Input
Assignments
You may recall the F2-04AD-1, (L) module requires 16 discrete input points in the
CPU. You can use these points to obtain:
S an indication of which channel is active
S the digital representation of the analog signal
S module diagnostic information
Since all input points are automatically mapped into V-memory, it is very easy to
determine the location of the data word that will be assigned to the module.
F2-04AD-1
Slot 1
Slot 2
Slot 3
8pt
Input
8pt
Input
16pt
Input
16pt
Input
X0
-X7
X10
-X17
X20
-X37
X40
-X57
V40400
MSB
X XXX
3 3 3 3
7 6 5 4
Analog Data
Bits
V40402
V40401
Data Bits
Slot 4
16pt
Output
Y0
-Y17
V40500
LSB
X
2
0
Within these word locations, the individual bits represent specific information about
the analog signal.
The first twelve bits represent the analog
V40401
data in binary format.
MSB
LSB
Bit
Value
Bit
Value
0
1
6
64
1 1 1 1 1 19 8 7 6 5 4 3 2 1 0
1
2
7
128
5 4 3 21 0
2
4
8
256
3
8
9
512
= data bits
4
16
10
1024
5
32
11
2048
DL205 Analog Manual 7th Ed. Rev. B 4/10
F2--04AD--1, (L)
4-Ch. Current Input
Slot 0
2--12
F2-04AD-1, F2-04AD-1L 4-Channel Analog Current Input
F2--04AD--1, (L)
4-Ch. Current Input
Active Channel
Indicator Inputs
Module
Diagnostic
Inputs
Two of the inputs are binary-encoded to
indicate the active channel (remember,
the V-memory bits are mapped directly
to discrete inputs). The inputs are
automatically turned on and off to
indicate the active channel for each
scan.
Scan
X35 X34
Channel
N
Off
Off
1
N+1
Off
On
2
N+2
On
Off
3
N+3
On
On
4
N+4
Off
Off
1
The last two inputs are used for module
diagnostics.
Module Busy — The first diagnostic
input (X36 in this example) indicates a
“busy” condition. This input will always
be active on the first PLC scan, to tell the
CPU the analog data is not valid. After
the first scan, the input usually only
comes on when extreme environmental
(electrical) noise problems are present.
The programming examples in the next
section shows how you can use this
input. The wiring guidelines shown
earlier in this chapter provide steps that
can help reduce noise problems.
V40401
MSB
LSB
X X
3 3
5 4
X
2
0
= channel inputs
V40401
MSB
LSB
X X
3 3
7 6
X
2
0
= diagnostic inputs
Note: When using the pointer
method, the value placed into the
V-memory location will be 8000
instead of the bit being set.
Channel Failure — The last diagnostic input (X37 in this example) indicates the
analog channel is not operating. For example, if the 24 VDC input power is missing or
if the terminal block is loose, the module will turn on this input point. The module also
returns a data value of zero to further indicate there is a problem.
The next section, Writing the Control Program, shows how you can use these inputs
in your control program.
Module
Resolution
Since the module has 12-bit resolution,
the analog signal is converted into 4096
counts ranging from 0 -- 4095 (212). For
example, a 4mA signal would be 0 and a
20mA signal would be 4095. This is
equivalent to a a binary value of 0000
0000 0000 to 1111 1111 1111, or 000 to
FFF hexadecimal. The diagram shows
how this relates to the signal range.
Each count can also be expressed in
terms of the signal level by using the
equation shown.
DL205 Analog Manual 7th Ed. Rev. B 4/10
4 -- 20mA
20mA
4mA
0
4095
Resolution = H − L
4095
H = high limit of the signal range
L = low limit of the signal range
16mA / 4095 = 3.907uA per count
F2-04AD-1, F2-04AD-1L 4-Channel Analog Current Input
2--13
Writing the Control Program
Reading Values:
Pointer Method
and Multiplexing

230
 

240 250-- 1 260
NOTE: DL250 CPUs with firmware release version 1.06 or later support this
method. If you must use the DL230 example, module placement in the base is very
important. Review the section earlier in this chapter for guidelines.
The example program shows how to setup these locations. Place this rung
anywhere in the ladder program, or in the initial stage if you are using stage
programming instructions. This is all that is required to read the data into V-memory
locations. Once the data is in V-memory you can perform math on the data,
compare the data against preset values, and so forth. V2000 is used in the example
but you can use any user V-memory location. In this example the module is installed
in slot 2. You should use the V-memory locations for your module placement. The
pointer method automatically converts values to BCD (depending on the LD
statement in the ladder logic).
SP0
LD
K 04 00
- or -
LD
K 84 00
Loads a constant that specifies the number of channels to scan and
the data format. The upper byte, most significant nibble (MSN)
selects the data format (i.e. 0=BCD, 8=Binary), the LSN selects the
number of channels (i.e. 1, 2, 3, or 4).
The binary format is used for displaying data on some operator
interfaces. The DL230/240 CPUs do not support binary math
functions, whereas the DL250 does.
OUT
V7662
Special V-memory location assigned to slot 2 that contains the
number of channels to scan.
LDA
O2000
This loads an octal value for the first V-memory location that will be
used to store the incoming data. For example, the O2000 entered
here would designate the following addresses.
Ch1 -- V2000, Ch2 -- V2001, Ch3 -- V2002, Ch 4 -- V2003
OUT
V7672
The octal address (O2000) is stored here. V7672 is assigned to slot
2 and acts as a pointer, which means the CPU will use the octal
value in this location to determine exactly where to store the
incoming data.
DL205 Analog Manual 7th Ed. Rev. B 4/10
F2--04AD--1, (L)
4-Ch. Current Input
Pointer Method
There are two methods of reading values:
S The pointer method
S Multiplexing
You must use the multiplexing method when using a DL230 CPU. You must also
use the multiplexing method with remote I/O modules (the pointer method will not
work). You can use either method when using DL240, DL250--1 and DL260 CPUs,
but for ease of programming it is strongly recommended that you use the pointer
method.
The DL205 series has special V-memory locations assigned to each base slot that
greatly simplify the programming requirements. These V-memory locations allow
you to:
S specify the data format
S specify the number of channels to scan
S specify the storage locations
2--14
F2-04AD-1, F2-04AD-1L 4-Channel Analog Current Input
The tables below show the special V-memory locations used by the DL240,
DL250--1 and DL260 for the CPU base and local expansion base I/O slots. Slot 0
(zero) is the module next to the CPU or D2--CM module. Slot 1 is the module two
places from the CPU or D2--CM, and so on. Remember, the CPU only examines the
pointer values at these locations after a mode transition. Also, if you use the DL230
(multiplexing) method, verify that these addresses in the CPU are zero.
The Table below applies to the DL240, DL250--1 and DL260 CPU base.
CPU Base: Analog Input Module Slot-Dependent V-memory Locations
F2--04AD--1, (L)
4-Ch. Current Input
Slot
0
1
2
3
4
5
6
7
No. of Channels
V7660 V7661 V7662 V7663 V7664 V7665 V7666 V7667
Storage Pointer
V7670 V7671 V7672 V7673 V7674 V7675 V7676 V7677
The Table below applies to the DL250--1 or DL260 expansion base 1.
Expansion Base D2--CM #1: Analog Input Module Slot-Dependent V-memory Locations
Slot
0
1
2
3
4
5
6
7
No. of Channels
V36000 V36001 V36002 V36003 V36004 V36005 V36006 V36007
Storage Pointer
V36010 V36011 V36012 V36013 V36014 V36015 V36016 V36017
The Table below applies to the DL250--1 or DL260 expansion base 2.
Expansion Base D2--CM #2: Analog Input Module Slot-Dependent V-memory Locations
Slot
0
1
2
3
4
5
6
7
No. of Channels
V36100 V36101 V36102 V36103 V36104 V36105 V36106 V36107
Storage Pointer
V36110 V36111 V36112 V36113 V36114 V36115 V36116 V36117
The Table below applies to the DL260 CPU expansion base 3.
Expansion Base D2--CM #3: Analog Input Module Slot-Dependent V-memory Locations
Slot
0
1
2
3
4
5
6
7
No. of Channels
V36200 V36201 V36202 V36203 V36204 V36205 V36206 V36207
Storage Pointer
V36210 V36211 V36212 V36213 V36214 V36215 V36216 V36217
The Table below applies to the DL260 CPU expansion base 4.
Expansion Base D2--CM #4: Analog Input Module Slot-Dependent V-memory Locations
Slot
0
1
2
3
4
5
6
7
No. of Channels
V36300 V36301 V36302 V36303 V36304 V36305 V36306 V36307
Storage Pointer
V36310 V36311 V36312 V36313 V36314 V36315 V36316 V36317
DL205 Analog Manual 7th Ed. Rev. B 4/10
F2-04AD-1, F2-04AD-1L 4-Channel Analog Current Input
Reading Values
(Multiplexing)

230
 

240 250-- 1 260
2--15
The DL230 CPU does not have the special V-memory locations that allow you to
automatically enable the data transfer. Since all channels are multiplexed into a
single data word, the control program must be setup to determine which channel is
being read. Since the module appears as X input points to the CPU, it is very easy to
use the active channel status bits to determine which channel is being monitored.
Note, this example is for a module installed as shown in the previous examples. The
addresses used would be different if the module was installed in a different I/O
arrangement. You can place these rungs anywhere in the program, or if you are
using stage programming place them in a stage that is always active.
ANDD
KFFF
Store Channel 1
X36
X34
X35
Store Channel 2
X36
X34
X35
Store Channel 3
X36
X34
X35
Store Channel 4
X36
X34
X35
Loads the complete data word into the accumulator.
The V-memory location depends on the I/O
configuration. See Appendix A for the memory map.
This instruction masks the channel identification
bits. Without this, the values used will not be correct
so do not forget to include it.
BCD
It is usually easier to perform math operations in
BCD, so it is best to convert the data to BCD
immediately. You can leave out this instruction if your
application does not require it.
OUT
V2000
When the module is not busy and X34 and X35 are
off, channel 1 data is stored in V2000.
OUT
V2001
When X34 is on and X35 is off, channel 2 data is
stored in V2001.
OUT
V2002
OUT
V2003
When X34 is off and X35 is on, channel 3 data is
stored in V2002.
When both X34 and X35 are on, channel 4 data is
stored in V2003.
DL205 Analog Manual 7th Ed. Rev. B 4/10
F2--04AD--1, (L)
4-Ch. Current Input
Load Data when Module is not busy
X36
LD
V40401
2--16
F2-04AD-1, F2-04AD-1L 4-Channel Analog Current Input
Single Channel
Selected
Since you do not have to determine which channel is selected, the single channel
program is even more simple.
Store Channel 1 when Module is not busy
X36
X34
X35
LD
V40401
Loads the complete data word into the accumulator.
The V-memory location depends on the I/O
configuration. See Appendix A for the memory map.
ANDD
KFFF
F2--04AD--1, (L)
4-Ch. Current Input
BCD
OUT
V2000
Analog Power
Failure Detection
This instruction masks the channel identification bits.
Without this, the values used will not be correct so do
not forget to include it.
It is usually easier to perform math operations in BCD,
so it is best to convert the data to BCD immediately.
You can leave out this instruction if your application
does not require it.
When the module is not busy and X34 and X35 are
off, channel 1 data is stored in V2000.
The Analog module has an on-board processor that can diagnose analog input
circuit problems. You can easily create a simple ladder rung to detect these
problems. This rung shows an input point that would be assigned if the module was
installed as shown in the previous examples. A different point would be used if the
module was installed in a different I/O arrangement.
Multiplexing method
V2000
K0
X37
=
C1
OUT
V-memory location V2000 holds
channel 1 data. When a data value
of zero is returned and input X37 is
on, then the analog circuitry is not
operating properly.
Pointers method
V2000
K8000
=
Scaling the
Input Data
Most applications usually require
measurements in engineering units,
which provides more meaningful data.
This is accomplished by using the
conversion formula shown.
You may have to make adjustments to
the formula depending on the scale you
choose for the engineering units.
C1
OUT
V-memory location V2000 holds
channel 1 data. When a data value
of 8000 is returned, then the analog
circuitry is not operating properly.
Units = A H − L
4095
H = High limit of the engineering
unit range
L = Low limit of the engineering
unit range
A = Analog value (0 -- 4095)
For example, if you wanted to measure pressure (PSI) from 0.0 to 99.9 then you
would have to multiply the analog value by 10 in order to imply a decimal place when
you view the value with the programming software or a handheld programmer.
Notice how the calculations differ when you use the multiplier.
DL205 Analog Manual 7th Ed. Rev. B 4/10
2--17
F2-04AD-1, F2-04AD-1L 4-Channel Analog Current Input
Analog Value of 2024, slightly less than half scale, should yield 49.4 PSI
Example without multiplier
Example with multiplier
Units = A H − L
4095
Units = 10 A H − L
4095
Units = 2024 100 − 0
4095
Units = 20240 100 − 0
4095
Units = 49
Units = 494
Handheld Display
Handheld Display
V 2001 V 2000
0000 0494
This value is more accurate
The following example shows how you would write the program to perform the
engineering unit conversion. This example assumes you have BCD data loaded
into the appropriate V-memory locations using instructions that apply for the model
of CPU you are using.
Note: this example uses SP1, which is always on. You
could also use an X, C, etc. permissive contact.
SP1
LD
V2000
When SP1 is on, load channel 1 data to the accumulator.
MUL
K1000
Multiply the accumulator by 1000 (to start the conversion).
DIV
K4095
Divide the accumulator by 4095.
OUT
V2010
Analog and
Digital Value
Conversions
Store the result in V2010.
Sometimes it is useful to be able to quickly convert between the signal levels and
the digital values. This is especially helpful during machine startup or
troubleshooting. The following table provides formulas to make this conversion
easier.
Range
4 to 20mA
If you know the digital value...
If you know the analog signal level...
A = 16D + 4
4095
D = 4095 (A − 4)
16
For example, if you have measured the
signal as 10mA, you can use the formula
to easily determine the digital value that
will be stored in the V-memory location
that contains the data.
D = 4095 (A − 4)
16
4095
D=
(10mA – 4)
16
D = (255.93) (6)
D = 1536
DL205 Analog Manual 7th Ed. Rev. B 4/10
F2--04AD--1, (L)
4-Ch. Current Input
V 2001 V 2000
0000 0049
2--18
F2-04AD-1, F2-04AD-1L 4-Channel Analog Current Input
Filtering Input
Noise (DL250--1,
DL260 CPU Only)
   
F2--04AD--1, (L)
4-Ch. Current Input
230
240 250-- 1 260
Add the following logic to filter and smooth analog input noise in DL250--1 and
DL260 CPUs. This is especially useful when using PID loops. Noise can be
generated by the field device and/or induced by field wiring.
The analog value in BCD is first converted to a binary number because there is not a
BCD-to-real conversion instruction. Memory location V1400 is the designated work
space in this example. The MULR instruction is the filter factor, which can be from
0.1 to 0.9. The example uses 0.2. A smaller filter factor increases filtering. You can
use a higher precision value, but it is not generally needed. The filtered value is then
converted back to binary and then to BCD. The filtered value is stored in location
V1402 for use in your application or PID loop.
NOTE: Be careful not to do a multiple number conversion on a value. For example,
if you are using the pointer method to get the analog value, it is in BCD and must be
converted to binary. However, if you are using the conventional method of reading
analog and are masking the first twelve bits, then it is already in binary and no
conversion using the BIN instruction is needed.
SP1
LD
V2000
BIN
BTOR
Converts the BCD value in the accumulator to
binary. Remember, this instruction is not
needed if the analog value is originally
brought in as a binary number.
Converts the binary value in the accumulator
to a real number.
SUBR
V1400
Subtracts the real number stored in location
V1400 from the real number in the accumulator,
and stores the result in the accumulator. V1400
is the designated workspace in this example.
MULR
R0.2
Multiplies the real number in the
accumulator by 0.2 (the filter factor),
and stores the result in the
accumulator. This is the filtered value.
ADDR
V1400
Adds the real number stored in
location V1400 to the real number
filtered value in the accumulator, and
stores the result in the accumulator.
OUTD
V1400
RTOB
BCD
OUT
V1402
DL205 Analog Manual 7th Ed. Rev. B 4/10
Loads the analog signal, which is a BCD value
and has been loaded from V-memory location
V2000, into the accumulator. Contact SP1 is
always on.
Copies the value in the accumulator to
location V1400.
Converts the real number in the
accumulator to a binary value, and
stores the result in the accumulator.
Converts the binary value in the accumulator
to a BCD number. Note: The BCD instruction
is not needed for PID loop PV (loop PV is a
binary number).
Loads the BCD number filtered value from
the accumulator into location V1402 to use in
your application or PID loop.
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