The RMC685 and RTC685 are single-channel DIN rail mounted industrial transmitters for temperature sensors and for signal conversion. A thermocouple, an RTD, or an analog process signal (mA or V) can be connected to the input. Various processing options are provided: filtering, table linearization, and custom functions.

An analog output (mA or V) is provided, along with an RS-485 serial bus. The serial bus supports the Nokeval

SCL and the Modbus RTU protocols.

The model RMC685 is equipped with a small display and a joystick to enable local configuration and for troubleshooting. RTC685 lacks the display. The devices can also be configured with a computer and a programming cable, or remotely over the RS-485 bus.

Each functional block is independent and interacts the other functions minimally unless configured to do so, which obviates the need to study and configure all the functions before using the device.

The device has two galvanic isolations. The supply is isolated, and the input is isolated. The remaining ports share a common ground.

WARNINGS

Although the input is galvanically isolated and type-tested with a 1 kV voltage, the isolation is only functional. For safety, the input or output signals must not be connected to a voltage potential more than 50

V AC or 120 V DC with respect to earth.

Connecting a four-wire RTD sensor in a transmitter configured for mA input and having the external transmitter supply enabled may result in damage for the sensor, as the sensor may not tolerate 15 volts. The transmitter is factory-configured for an RTD sensor.

TRADEMARKS

This device uses the FreeRTOS real-time operating system version 6.0.0. The source code of the RTOS is available on request – contact [email protected]

MANUFACTURER

Nokeval Oy

Rounionkatu 107

FI-37150 Nokia

Finland

Tel +358 3 3424800 (Mo-Fr 8:30-16:00 EET)

WWW http://www.nokeval.com/ email [email protected]

, [email protected]

QUICK SET-UP

Connections overview

Analog out RS-485 bus

A 1 2 3 4

B 1 2 3 4

Pwr/Alm

Serial

1 2 3 4 D

POL

C 1 2 3 4

C D

10V in

D 1 2 3 4 D 1 2 3 4 D 1 2 3 4

Power supply 24 V DC RTD sensor TC sensor mA in

Figure 1

Quick configuration

The most typical configuration settings can be set at the quick configuration menu. For advanced functionality, refer to the later chapters.

To enter the quick configuration menu, press the joystick inwards one second (RMC685 only). Then move the joystick up or down to find “QConf”. Press the joystick inwards or to right to enter the quick configuration menu.

Use joystick up-down movements to browse the items, and if a value is not what desired, press the joystick inwards. While the value is blinking, use the joystick movements to edit the value, and finally press the

joystick inwards to finish the editing. For a detailed explanation of editing the values, refer to page 18.

When all the settings are done, press the joystick two times to left to return to the normal display.

Item Description

Sensor

Wires

InLo

Input signal type.

 0-10V

 0-20mA

 4-20mA

 Pt100

 TcJ (thermocouple J)

 TcK (thermocouple K)

 TcN (thermocouple N)

 TcS (thermocouple S)

Number of Pt100 sensor wires. Visible with a Pt100 sensor only.

Input low end scaling. The displayed engineering value at the low end of the input signal, e.g. at 4 mA signal on 4-20 mA range. Not visible on temperature sensors.

InHi

Input high end scaling. The displayed engineering value at the high end of the input signal, e.g. at 20 mA signal on 4-20 mA range. Not visible on temperature sensors.

Number of digits to show after the decimal point. Affects the display

Dec

only.

OutRng

Analog output signal type and range.

 0-10V

 0-20mA

 4-20mA.

OutLo

OutHi

Output low end scaling. The displayed engineering value that will make the output signal to be at its low end, e.g. 4 mA on 4-20 mA range.

Output high end scaling.

Factory default

Pt100

100

4-20mA

100

A mixed use of the quick and the full configuration menu is not recommended, since using the quick configuration will affect (and possibly overwrite) multiple settings in the full menu. Changing the settings in the quick configuration menu will affect the following settings: Input/Sensor, Input/R0,

Input/Wires, Output/Range, Output/Lo, Output/Hi, UI/Screens/1/Upper/Src, UI/Screens/1/Upper/Text,

UI/Screens/1/Lower/Src, UI/Screens/1/Lower/Dec, UI/Screens/1/Lower/Text.

INSTALLING

Mounting

The transmitter is intended to be mounted on a standard 35 mm DIN rail. Hook the groove in the back of the transmitter to the outer lip of the rail and tilt the device until the lock engages. To remove, pull the lock downwards with a flat screwdriver.

The mounting position is free, but for maximum accuracy with thermocouples, an “upright” position is recommended: connectors A-B on top. With thermocouples, avoid heat sources near the input connector.

Jumpers

This device does not have user-configurable jumpers.

Connections

The connector blocks are detachable for easier wiring. Use a flat-bladed screwdriver to carefully lever them off. When levering the connector D, take care not to damage the blue cold junction temperature sensor behind the connector block.

The connections are explained in detail in the relevant chapters. A quick overview is in Figure 1 on page 4.

Power supply

This device requires a 24 V DC supply connected to connector C. The positive line is connected to terminal C1 and negative in C2. Reverse polarity will not damage the device. The supply is galvanically isolated from the other ports.

MAINTENANCE

Cleaning

The plastic parts can be cleaned with a soft cloth and soap water or isopropyl alcohol. The cloth must be damp but not wet. With the model RMC685, it is especially important to avoid water entrance between the LCD glass and the plastic front panel.

Recalibration

When maximal accuracy is important, it is recommended to recalibrate the transmitter annually at the manufacturer.

Calibration certificate

A calibration certificate for a new or recalibrated device can be downloaded for free at Nokeval web site based on the serial number.

OPERATION

Registers

The continuously varying values, e.g. measured input reading, table output, state of the digital input, and the results of the ELo program, are collected in a 1-dimensional table, called the table of registers.

The different operational blocks of the transmitter are configured to watch one or more registers. The analog output is most often configured to watch, or follow, the measured input reading, but can be configured to follow any other register for advanced functionality.

Here is a complete list of the registers:

Register

DigiIn

Number Description

Measured, scaled and filtered input reading.

Measured cold junction temperature.

State of the digital input. 0=passive, 1=active.

Table

Out

Setp1

Setp2

F1…F12

8…19

Ser1…Ser2

20…21

Screen

Keys

Output of the (linearization) table.

Analog output in mA or V.

Setpoint value 1.

Setpoint value 2.

ELo registers.

Serial bus controlled registers.

Currently displayed screen number 1…4.

State of the joystick.

The current register values can be viewed with the Monitor function (RMC685 only): Press * the joystick inwards one second and browse ^v to Monitor. Enter with >. Browse the items with ^v. Finally exit with <.

Self-diagnostics messages

The transmitter may detect some internal or external problems. The messages can be viewed in the

diagnostics menu. Using the integral display, see Self-diagnostics on page 20. Using Mekuwin, refer to its

documentation. The messages are:

Message

EEPROM

ADC error

Sensor fault

Math error

Description

The internal non-volatile memory storing the configuration settings and the factory calibration values is either faulty or the contents have been corrupted.

The microcontroller does not get a response from the A/D converter.

The input signal is not what it should be.

The ELo program has an error.

Corrective actions

Check all the configuration settings and save them to the EEPROM.

Cycle the power off-on.

If the message persists, the device needs service.

Check that the supply voltage is within specifications.

Try to disconnect the input connections.

The device needs service.

Check the condition of the sensor.

Check the input wiring.

Check the input settings.

Go to the configuration menu and check the

Math/Error and Math/ErrLine values to find the error.

CONFIGURING

This device can be configured using the integral display and joystick, or with an aid of a computer.

With the integral display (RMC685 only)

Using the display and the joystick is described in Configuration state, page 17.

With a programming cable

The programming cable to be used is Nokeval DCS772, connected to a USB port. Currently the PCB version must be V1.3 or newer (since the older ones lack the echo suppression which is required with the Modbus protocol). In addition, an adapter POL-3PIN is needed. The adapter is connected to the 3.5 mm plug of the

programming cable, and the other end to the RMC685 connector marked “POL” in Figure 1 on page 4.

POL-3PIN

USB DCS772

A free Microsoft Windows software Nokeval Mekuwin is used. About using Mekuwin, refer to its documentation. The contents of the target device configuration menu are described in the relevant sections of this manual.

The communications parameters are always:

Protocol

Baud

Parity

Address

Modbus RTU

9600

8E1

Over the serial bus

Mekuwin can be used over the RS-485 bus. The Mekuwin communications parameters must match the selections made in the device (Serial menu). Both Nokeval SCL and Modbus RTU protocols can be used.

Moreover, it is possible to change the configuration settings remotely by writing the appropriate Modbus

Holding registers. This is allowed only if the Serial/Conf setting is enabled in the transmitter configuration menu.

Configuration menu

The contents of the configuration menu are described in the relevant chapters. A quick overview is shown here. Some of the settings will be hidden when not used.

Conf

Input

Table

Math

Output

Serial

Agents

Screens

Setpoints

Passwords

Screens

Count

Scan

Setpoints

1...4

Upper

Lower

1...2

Min

Max

Upper/Lower

Src

Dec

Text

Table

Src

Pts

X10

Y10

Math

Program

Trigger

Error

ErrLine

Lopass

Pts

Mea1

Sca1

Mea2

Sca2

Input

Sensor

Wires

Unit

Supply

Pullup

Speed

MovAvg

Passwords

Conf

Serial

Protocol

Address

Baud

Parity

Dec

Conf

Agents

Output

Src

Range

Rdg1

Out1

Rdg2

Out2

Limit

Break

1...2

Src

Dest

INPUT

General

The configuration settings affecting the input are collected in the Input submenu of the configuration menu.

The final scaled and filtered input reading is placed in the

RTD sensors including Pt100

Connections

Before connecting an RTD sensor, make sure that the transmitter is not configured for mA input, because selecting a mA range and enabling the transmitter supply at terminal D1 could damage the sensor.

 Two-wire RTD: connect the sensor in terminals D2 and D4. Please note that the

D wiring resistance will cause significant error in the measurement, and a short cable must be used in this configuration.

 Three-wire RTD: connect one end of the sensor in terminals D3 and D4 (these wires usually share the same color), and the other end in terminal D2.

 Four-wire RTD: connect one end of the sensor in terminals D3 and D4, and the

Figure 2

1 2 3 4

+ other end in D1 and D2. Four-wire measurement yields the best accuracy and is recommended whenever possible.

The maximum sensor cable length is 30 m. A shielded cable earthed at one point near the transmitter is recommended in noisy environments.

Settings

In the Input submenu of the configuration menu, set

Sensor

to Pt, Ni, Cu, KTY83, or NTCLE3977.

Set the

setting to correspond to the nominal resistance of the sensor in ohms. For Pt100 and Ni100, the correct value is 100. For Pt1000, enter 1000.

If the precise resistance of the sensor is known (e.g. it is calibrated and marked on the sensor), it can be entered in R0 to reduce the sensor error.

For Pt and Ni sensors, the nominal resistance is the resistance at 0 °C. For Cu, KTY83, and NTCLE3977 sensors, it is the resistance at 25 °C.

The

Wires

setting must match the number of wires used to connect the sensor.

Select the measurement

Unit

: °C, °F, or K.

The input scaling is usually disabled by setting

Pts

to 0. The scaling options can be used to remove the

measurement errors as described in Sensor error correction on page 14.

Thermocouples

Connections

Connect the positive wire of the thermocouple sensor in terminal D3 and the negative wire in D4. Please note that if an extension cable is used, it must be intended for the thermocouple used, and the cable must be connected with correct polarity. With thermocouple K, the positive wire is usually green or brown.

D 1 2 3 4

The maximum cable length is 30 m. A shielded cable earthed at one point near the transmitter is recommended in noisy environments.

Figure 3

Settings

In the Input submenu of the configuration menu, select the correct thermocouple type in the

Sensor

setting.

The thermocouple options begin with Tc, e.g. TcK. The thermocouples supported are B, C, D, E, G, J, K, L, N, R,

S, and T. The measurement ranges for each of these are specified on page 35.

Select the measurement

Unit

: °C, °F, or K.

mA input

Connections

An active mA signal is connected to terminals D3 (positive) and D4. There is a 50 Ω shunt resistor between these inside the transmitter, accompanied with a self-resetting fuse, which will increase the total resistance to approx. 70 Ω. When the transmitter is powered off, the current cannot flow through it.

D 1 2 3 4

This transmitter can supply an external transmitter with 15 V ±10%, max 50 mA. The supply must be enabled with a configuration setting

Supply

. This supply is available between terminals D1 (positive) and D4. The supply shares the negative terminal of the mA input.

An external two-wire (passive) transmitter can be connected between terminals D1

(positive) and D3. The supply has to be engaged with the

Supply

configuration setting.

The external transmitter must not require more than 12 V supply voltage.

Figure 4

The maximum cable length is 30 m.

Settings

When the input signal is a standard 0-20 or 4-20 mA signal, select the appropriate range in the

Sensor

setting in the Input submenu of the configuration menu. Scale the signal with the

and

settings. The scaling is used to convert the raw mA reading to a meaningful engineering value, e.g. a pressure reading. The engineering value corresponding to the low end of the signal (4 mA on the 4-20 mA range) is entered in the Lo setting, and the high end in the Hi setting. Example: a pressure transmitter gives a signal of 4-20 mA corresponding to a pressure range 0 to 6 bar: set Lo=0 and Hi=6.

For more exotic signals, select the smallest sufficient range among 24mA, 1.5mA, and 0.18mA. Each is capable to measure negative current too. If a scaling is desired, use the Pts and the Mea/Sca settings as described in

Advanced scaling on page 13.

If the supply for an external transmitter is required, switch on the

Supply

setting.

Fault detection

On the 4-20mA range, an input signal below 3.68 or above 20.8 mA for more than 30 samples (4 seconds on

Normal speed) is considered to indicate fault to conform to Namur NE 43. Dashes will be displayed, and the analog output will behave as configured with its Break setting.

Voltage inputs

Connections

For ranges 9mV, 70mV, 290mV, and 1100mV, use terminal D3 for the positive wire, and terminal D4 for the other.

For ranges ±1100mV, 0-10V, and 11 V, use terminal D1 (positive) and D4. Before connecting a signal in this configuration, make sure that the transmitter is not configured for a mA input with the supply option enabled to prevent a damage that could be caused by the 15 V transmitter supply.

D 1 2 3 4

The maximum cable length is 30 m. With small signals and also in extremely noisy environments, a shielded cable earthed at one point near this transmitter is recommended.

Figure 5

Settings

If using the standard signal of 0-10 V, set the Sensor setting in the Input submenu of the configuration menu to 0-10V. Scale the signal with the

and

settings. The scaling is used to convert the raw voltage reading to a meaningful engineering value, e.g. a pressure reading. The engineering value corresponding to 0 V signal is entered in the Lo setting, and the 10 V value in the Hi setting. Example: a pressure transmitter gives a signal of

0-10 V corresponding to a pressure range 0 to 6 bar: set Lo=0 and Hi=6.

With other than 0-10 V signal, select one of the ranges 9mV, 70mV, 290mV, 1100mV, ±1100mV, 11V in the

Sensor setting. Select the smallest sufficient range in order to obtain the best accuracy. All the ranges can measure negative voltage at least to -70 mV; the ±1100mV and 11V ranges can measure -1100 and -11V respectively. The reading is expressed in the units corresponding to the name of the range (volts in 11V range, millivolts otherwise). If desired, use the two-point scaling (Pts and Mea/Sca settings) to scale the voltage to an

engineering value as described in Advanced scaling on page 13.

Resistance input and potentiometer

Refer to the RTD connections on page 10.

The resistance input can be used to measure an RTD that is not directly supported by this transmitter. The linearization table function may be used to handle the sensor non-linearity.

Another use of the resistance input is to read a potentiometer in a variable resistance configuration. The potential divider connection, also known as slidewire, is not supported by this transmitter. Select the smallest sufficient ohm range in the Sensor setting, and use the two-point scaling to convert the ohms to a meaningful

position reading as described in Potentiometer teaching on page 14.

Common input settings

Sensor fault detection

With mV, thermocouple, RTD and ohm inputs, this transmitter is able to intermittently inject a small 100 nA current to the sensor wires in order to detect a failed sensor or wiring. The sensor fault detection is enabled by setting the

Pullup

setting on. It is generally recommended to keep this setting on, but when requiring the lowest noise or using a high-impedance voltage source, the setting should be set off.

On the 4-20mA range, an input signal below 3.68 or above 20.8 mA for more than 30 samples (4 seconds on

Normal speed) is considered to indicate fault to conform to Namur NE 43.

When an input fault is detected, the

register will indicate fault instead of having a reading. The other functions of the transmitter then behave as they are programmed to do in such a situation. The display will show dashes (-----) etc.

Measurement speed

The

Speed

setting defines the A/D conversion rate and some internal settling times. The noise and accuracy specifications are given for the Normal speed. A lower noise can be achieved by selecting Slow.

Correspondingly selecting a faster speed will increase the noise (flicker) of the input reading, and can also reduce the accuracy overall. The faster speeds should be used only when really necessary.

Approximate update rate in Hz on different speed settings:

Slow

Normal

Brisk

Fast

Super

1.9

7.8

15.6

100

The speed, especially the highest speeds, depends on the other functions of the transmitter.

Please note that the analog output of RMC685 is not fast, and the fastest measurement speeds can be utilized via the serial bus only.

Filters

Noise and short disturbances in the input reading can be attenuated with two kinds of filters. The filters can be used simultaneously.

The moving average filter has a finite impulse response. It remembers the selected amount of latest readings and averages them. The number of samples is configured in the MovAvg setting. Due to the limited memory, the maximum number of samples is 20. When this kind of filtering is not desired set MovAvg to 1.

The 1 st

order lowpass filter has infinite impulse response, which means that after a step change in input signal the filtered reading will approach the new value forever in theory. First fast, then slower and slower. The main advantage is that, unlike the moving average filter, the lowpass filter can be configured to attenuate very strongly. Also in a control loop, the 1 st

lowpass is easier to handle than the moving average. The time constant is given in seconds. A setting of 0 disables the filter.

Advanced scaling

On non-standard input ranges the input can be scaled to an engineering value using the two-point free scaling.

To enable the two-point scaling, set the

Pts

setting to 2.

Enter the first “raw” or unscaled reading in Mea1 setting, and the corresponding engineering or scaled reading in Sca1. Do the same for the Mea2/Sca2 pair. Linear interpolation is used between these points, and linear extrapolation outside.

Example: input signal is 1-5 V, corresponding to a flow of 0 to 10 m

/h:

 Sensor = 11V (the smallest sufficient range)

 Mea1 = 1 (volts)

 Sca1 = 0 (m

/h)

 Mea2 = 5 (volts)

 Sca2 = 10 (m

/h)

The scaling can also be performed with the Table function, either alone or combined with this scaling.

Sensor error correction

To enhance the measurement accuracy of the combination of this transmitter and the sensor, a one- or twopoint calibration can be performed e.g. in a thermal bath with an accurate reference meter.

To do a one-point correction, set

Pts

to 1. Give a Lock command (see below) for the

Mea1

setting, which will make the transmitter to copy the current uncorrected input reading to Mea1. Then enter the reference meter reading in

Sca1

. The Mea1 and Sca1 values should be quite close to each other when correcting a small sensor error. The transmitter will add a value of Sca1 minus Mea1 to every reading - it is an offset correction.

A two-point correction is done similarly to the one-point correction, but Pts is set to 2 and the operation is performed on Mea2/Sca2 pair in addition to Mea1/Sca1. The transmitter will then use linear interpolation and extrapolation to correct the reading.

If more than two points are needed, use the Table function instead of the input scaling. Its operation principle is very similar, but it provides up to 10 points. All the other functions (display, analog output, etc.) must then be changed to follow the Table register instead of the In register.

To disable the sensor error correction, set Pts to 0. Changing Pts will not destroy the Mea and Sca values, although they may be hidden.

The

Lock command

is given in Mekuwin by clicking the L button next to the value. On the integral display

(RMC685), browse to the item (Mea1 or Mea2) but do not start editing – nothing should be blinking. Now press the joystick one second, and a pop-up menu appears. Select Lock.

Potentiometer teaching

This transmitter can read a potentiometer by measuring its resistance. What the transmitter sees is ohms. To convert the ohms to a meaningful value, e.g. position or angle, use the two-point scaling.

First set Pts to 2. Move the potentiometer to the first teaching position. Give a Lock command (see Sensor error correction) for the Mea1 setting to copy the current ohms reading to Mea1. Enter the corresponding

engineering value in Sca1. Repeat the operation on Mea2/Sca2 pair.

DIGITAL INPUT

The digital (switch) input can be used alongside the ELo program. The current switch state is available in the

DigiIn register. The input is read every 50 ms. There is no additional debounce logic.

The input is of NPN type. The terminal B1 is pulled to 3.3 V internally by a 10 kΩ resistor. When the terminals

B1 and B2 are shorted externally, the input is considered to be in its active state, and a value of 1 is placed in the DigiIn register. When the terminal B1 is floating or connected to a voltage higher than 2.5 V, the DigiIn register will contain 0.

There are no configuration settings related to the digital input.

Min

Max

ANALOG OUTPUT

The analog output settings are in the Output submenu of the configuration menu.

Connections

An active mA signal is obtained from terminal A1, and the current must return to A3.

A voltage output is available between terminals A2 (positive) and A3.

A 4 3 2 1

The mA and V outputs can’t be used simultaneously.

Source

Figure 6

The analog output usually follows the scaled and filtered input reading, which is obtained by selecting In in the

Src

setting. It is possible to select any other register. The analog output can be taken from the Table output, from a Setpoint register, from an ELo program controlled register, or controlled with the serial bus.

Range and scaling

The output has two kinds of scaling: fixed range and free. Fixed scaling is used to easily generate a standard signal, while the free scaling can produce exotic scalings.

If the output signal desired is any of 0-20 mA, 4-20 mA, or 0-10 V, select the corresponding range in the

Range

setting. Enter the low end scaling in the

setting and the high end scaling in the

setting. When the input value obtained from the register selected with Src corresponds to the Lo setting, the output will be at the low end of the range, e.g. 4 mA if using the 4-20 mA range.

For any other output range, select a free range mA or V in the Range setting. Then use the Rdg and Out settings to scale. When the input value corresponds to Rdg1, the physical output will be Out1 mA or V. When the input corresponds to Rdg2, the output will be Out2. Linear interpolation and extrapolation is used.

An example of free scaling: Generate 1-5 V signal when the input is 0-100 °C. Select V range, and enter

Rdg1=0, Out1=1 (volts), Rdg2=100, Out2=5.

Limit and break

The

Limit

setting defines if the analog output is allowed to go beyond the range. If enabled, the output is limited within the range selected with the Range setting, or between the Out1 and Out2 when using the free scaling. In addition, on the 4-20mA range the output is limited between 3.8 and 20.5 mA (NAMUR NE 43).

The

Break

setting defines how the analog output behaves in a fault condition, e.g. when the analog output is configured to follow the input and the sensor is found to be faulty.

The analog output will go to the lowest signal possible – 0 mA or 0 V, even if Limit is enabled. On the fixed 4-20mA range the output will go to 3.5 mA.

The analog output will go to the low end of the range, e.g. 4 mA when using the 4-20 mA range, or to the Out1 value when using the free scaling.

The analog output will go to the high end of the range, e.g. 20 mA.

The analog output will go to approx. 22.5 mA or 11 V, even if Limit is enabled.

USER INTERFACE

The term user interface refers to the LCD display, the joystick, and the two LED indicators in the face of the

RMC685 transmitter. The user interface can be used to watch the desired values, to configure the transmitter, and to assist in troubleshooting.

The joystick operations are symbolized with <^v> and * in this chapter. The triangles should be selfexplanatory. Symbol * means pressing the joystick inwards.

The user interface has various states:

State Description

Normal

The contents of the display can be customized, but most typically it indicates the current input reading and analog output value. Also allows changing the setpoint values.

Quick config

Configuring the transmitter with a minimal set of options.

Explained at

Normal state and the screens, page 20.

Configuration

Viewing and editing all the configuration settings to alter the operation of the transmitter.

Monitor

Diagnostics

Calibration

Viewing the values of the registers, used mostly in troubleshooting.

Shows the internal or external faults detected.

For factory calibration.

Quick configuration, page

Configuration state, page

17.

Monitoring and simulating, page 19.

Self-diagnostics, page 20.

Not in this manual.

Configuration state

The configuration state is used to view and alter the configuration settings concerning the various functions of this transmitter. An alternative way to configure is to use a programming cable or a serial bus along with

computer software Mekuwin, as explained on page 8.

Entering

To enter the configuration state, press the joystick inwards (symbol * used in this manual) one second. In the menu, select ^v Conf and press *. If a configuration password has been set, it must be entered now. The password consists of six joystick movements <^v>. If an incorrect password is entered, the display will shortly indicate “Wrong” and return to the normal state.

Navigating

Enter main menu

1 sec *

^ v

Conf

QConf

Monito

Diag

Exit

<-Save

<-Undo

Enter Conf menu

Exit Conf

^ v

Input

Table

Math

Output

Serial

Agents

--- Navigating Editing ---

Enter a submenu

Sensor

^ v

Wires

Unit

...

Return from a submenu

Edit a value

Done

Sensor

Blinking

Use <^v> to edit.

Press * 1 sec for a pop-up menu.

Figure 7

The configuration menu is organized hierarchically for clarity. The first level contains submenus for each functional block of the transmitter: The user interface, input, table, ELo program, analog output, serial bus, and agents.

Browse the submenus using the up/down movement ^v of the joystick. Enter the desired menu by pressing the joystick inwards * or to the right >. In the submenu, again browse the contents with ^v. The upper row indicates the name of the submenu or the setting, while the lower row shows the current setting value, or “-

>” when the item is a submenu.

To start editing a setting value, press the joystick inwards * or to the right >. (A text “Agent” will be shown briefly if the setting is controlled by an agent.) The whole value or one digit of it starts blinking. Different types of values are edited in different ways, as detailed below. To stop editing, press the joystick inwards *.

Press < to exit to the previous menu level.

Editing floating point values

Floating point values have a decimal point. The input and output scalings use floating point numbers, as an example. One digit is blinking when editing. The blinking digit can be changed – or in other words the cursor moved – with <>. The digit can be increased with ^ and decreased with v. Actually the whole number is increased and decreased instead of a single digit, e.g. if the first number to the left from the decimal point is blinking, the number is increased by one every time ^ is pressed. The number will go 1, 2, 3 … 9, 10, 11, etc.

To change the sign of the value, there are two ways:

1. Press the joystick inwards one second and select Negate from the pop-up menu.

2. If all digits on the right side of the cursor are zeros, the value can be decremented below zero or incremented above zero. E.g. initial value 2.00, pressing v several times will yield 1.00, 0.00, -1.00, -

2.00.

To reset the value (to 0): Press the joystick inwards one second and select Zero from the pop-up menu.

In some cases, it is possible to “push” the cursor against the right edge of the display making the display to scroll and reveal more decimals. Since some digits will temporarily roll out of the display on the left, a symbol

“_” will appear.

Editing integer values

The method to edit integers (e.g. the Dec and serial address settings) is quite similar to editing floating point numbers. When the cursor (blinking) is at the last digit, the value can be increased and decreased by 1 with joystick up/down movements. When the cursor is at the second last digit, the value will be increased or decreased by 10, etc.

To quickly reset the value to zero, press the joystick inwards one second and select Zero from the pop-up menu.

Editing options

Options, e.g. the sensor selection, are edited simply with joystick up/down movements.

Register and Meku references

The various Src settings are used to select a register as a source for a certain function like the analog output.

The agents also use Meku references, i.e. a reference to a setting in the configuration menu. In most cases it is also possible to set the reference to None.

The editor has two states for editing the references: the space selection state and the actual reference selection state. The space selection is used to switch between None, Meku, and Register spaces. In most cases it is not possible to choose between all the three spaces.

When the space has been selected, press > to enter the actual reference selection state.

A register reference is selected using ^v on the one-dimensional register list. Finally exit by pressing the joystick inwards *. Editing a Meku reference requires also <> movements due to the hierarchical nature of the configuration menu tree.

Space selection

^ v

None

Meku

SPACE

Reg

Exit

Item selection

^ v

REG

DigiIn

Table

Out

Setp1

Setp2

Entering a password

To set a configuration password, browse to UI/Password/Conf item and press *. The cursor starts to blink.

Now press the joystick six times to any direction <^v> but not *. To disable the password, press * twice.

Editing text

It is recommended to edit the text settings using a computer and Mekuwin software.

The blinking cursor can be moved with <>. The text will scroll when trying to advance the cursor outside the display. The character at the cursor can be changed with ^v.

The upper row has two numbers. The leftmost indicates the current cursor location in the text, 1 meaning the first character. The other indicates the ISO 8859-1 code of the character in hexadecimal format. A dot appears after the code when the character is lowercase.

By pressing one second * a pop-up menu appears.

will change the current character to N, which is in the middle of the alphabets.

Linefeed

adds a line feed (new line) character.

End

terminates the text at the cursor location, discarding all the characters to the right of the cursor.

Exiting

When exiting the first menu level, the transmitter will provide a menu containing options Save and Undo.

Select Save and press < to keep all the configuration changes done and to save them to the EEPROM, or alternatively select Undo and press < to discard all the changes made in this configuration session. The user interface returns to the normal state.

Monitoring and simulating

The monitor state is used to view the values of the registers. It is a great aid in troubleshooting.

The monitor state is entered by pressing the joystick inwards one second in the normal state and by selecting

Monitor in the menu. The monitor is a one-dimensional list of the registers. It can be browsed with ^v. The upper row of the display tells the item name. The value is visible on the lower row.

The In register can be “locked” to a simulation state in order to test the operation of the other functions without a need for different physical input values. Browse to the In item in the monitor menu. Press one second * and select Lock from the pop-up menu. The register is now locked and the value can be edited. The other functions configured to follow the In register act like the simulated value was a real input reading. To return to the normal operation, do the same, but select Free in the pop-up menu. The simulation state is also exit at power-off.

To exit the monitor state, press <.

Self-diagnostics

If the transmitter detects a problem in itself or in the external connections, it will activate an item in the diagnostics table. The Pwr/Alm LED will blink at about 4 Hz. When the LED blinks this way, head to the diagnostics menu: In the normal state, press * one second. Select Diag and enter with *. There may be more than one message – use ^v to check. Finally exit with <.

The diagnostics messages are explained on page 7.

LEDs

The user interface has two red LEDs. The Pwr/Alm led will normally shine steadily, but if the transmitter

detects an internal or external fault, the LED will blink, as explained in the section Self-diagnostics, page 7.

The Serial LED is active when this transmitter has received a valid message from the RS-485 bus. The Serial

LED blinks very fast in the bootloader mode (that allows upgrading the firmware on the field).

Normal state and the screens

The transmitter is in the normal state after power-up. The contents of the display depend solely on the configuration settings made in the UI/Screens submenu of the configuration menu. Up to four sets of display contents can be configured. These sets are called screens.

Default screen

By factory default, and always when changing the Sensor and OutRng settings in the

Quick configuration menu, the first screen is configured to have the input reading on the upper row and the output reading on the lower row, associated with a measurement unit in certain cases.

°C 25.6 mA 8.10

Switching among the screens

When more than one screen is configured, the user can switch the screen displayed by using the up and down movement of the joystick. Moving down will advance to a screen with a larger number.

It is also possible to configure the transmitter to intermittently change the screen displayed using the

UI/Screens/Scan

setting. The possible values are:

Manual

Spring

1 s

2 s

The screen displayed is not automatically changed. The screen can be changed with up/down movement of the joystick. After power-up, screen 1 is displayed.

The user can select the screen displayed with the joystick, but when not touching the joystick for five seconds, the screen 1 is displayed. This is intended for cases where the screen 1 contains the items to be viewed normally, but the user can in some situations need to access the other screens.

The transmitter will go through all the screens with one second interval. It is possible to temporarily to stop in a certain screen by pressing the joystick shortly up or down.

Like 1 s, but slower.

Defining a screen

The number of screens used is defined with the

Screens/Count

setting. Each screen has a submenu of its own.

The first screen is configured at submenu

Screens/1

Each screen submenu contains further two submenus,

Upper

for configuring the upper row of the display, and

Lower

for the lower row.

Each row submenu contains three settings: Src, Dec, and Text.

Src

is used to specify which register value should be shown on this row. Most typical register to show on the upper row of the first screen is the In register – the latest input reading. If no register value is to be shown, select None in the Src setting.

The number of digits to show after the decimal point is adjusted with the

Dec

setting. If requesting more decimals than can fit in the screen, the decimals are automatically dropped whenever possible.

With a negative Dec value, the corresponding amount of last digits is rounded to zero, e.g. if Dec is -2, the reading is rounded to nearest 100.

A fixed text can be displayed on the row by entering it in the

Text

setting. If the Src setting is not None, the text is displayed before the register value, which is convenient for adding a tag or a measurement unit. If the

Src setting is None, the text can occupy the whole row. Trailing spaces can be added to the text for adjusting the appearance. In addition to the standard ASCII characters, the following characters may be used: Å Ä Ö Ø Ü

° µ. It is however not possible to show all the characters properly on the 11-segment display.

Most typical usage is to define the screen 1 upper row to display the input reading (In register) and the lower row the output reading (Out register) possibly associated with a unit text:

UI/Screens/1/Upper/Src

UI/Screens/1/Upper/Dec

UI/Screens/1/Upper/Text

UI/Screens/1/Lower/Src

UI/Screens/1/Lower/Dec

UI/Screens/1/Lower/Text

°C

Out

2 mA

°C 25.6 mA 8.10

An alternative use is to define only the input reading on the lower row and a fixed “tag” text on the upper row. The other screens can then be configured to show the analog output and other significant values:

UI/Screens/1/Upper/Src

UI/Screens/1/Upper/Dec

UI/Screens/1/Upper/Text

UI/Screens/1/Lower/Src

UI/Screens/1/Lower/Dec

UI/Screens/1/Lower/Text

None

N/A

Pump 1

PUMP 1

300

Setpoints

A setpoint refers to a register the value of which can be easily adjusted by the operator in the normal state. It is not associated with alarm levels. The setpoint value can be used in various ways:

 To change the operation of the ELo program. The ELo program can read a setpoint register and use it as any other register.

 To manually control the analog output. If the Src setting of the analog output is set to Setp1 or Setp2, the analog output is defined by the setpoint value.

 To quickly access some numerical configuration setting without entering the configuration state. See

Setpoint controlled setting on page 34.

The setpoint value is a floating point number. The minimum and maximum allowed value for the first setpoint can be defined in the UI/Setpoints/1/Min and Max settings.

The setpoint value is stored in an EEPROM memory and is thus retained over power-off situations.

To show a setpoint in a certain screen, just set the other of the Src settings to Setp1 or Setp2. When the screen containing a setpoint register is viewed in the Normal state, the user can press the joystick: The setpoint value starts to blink and it can be increased and decreased with joystick up/down movements. An acceleration algorithm has been implemented. To finish adjusting the setpoint, press the joystick again.

It is not allowed to have a setpoint on both rows of one screen. The transmitter can’t know which one of them should be adjusted when the joystick is pressed.

An example of configuring the screen 2 to have a setpoint:

UI/Screens/2/Upper/Src

UI/Screens/2/Upper/Dec

UI/Screens/2/Upper/Text

UI/Screens/2/Lower/Src

UI/Screens/2/Lower/Dec

UI/Screens/2/Lower/Text

UI/Setpoints/1/Min

UI/Setpoints/1/Max

None

N/A

Level

Setp1

1 m

100

LEVEL

M 99.9

TABLE FUNCTION

The table function is most typically used to linearize a non-linear input signal or to remove the input signal errors in multiple points. It can be used for other purposes too, e.g. to generate a non-linear output signal or in co-operation with the ELo program.

The table function settings are collected in the Table submenu of the configuration menu.

The linearizer is configured to follow one register with the

Src

setting. Any register can be selected. To linearize the input, select the In register.

The table consists of 2 to 10 points that map the input value to an output value. The number of points is defined with the

Pts

setting.

Linear interpolation is used between the points. Outside the points, linear extrapolation is used obtained from the two nearest points. Each point has an

value and a

value. X is the input, and Y is the corresponding output. The operation is equivalent to the Pts/Mea/Sca scaling of the input, but allows more than two points.

When using more than two points, the X values of the points must be in ascending order: X1 is the smallest X value. This limitation does not apply to the Y values.

The table output is available in the Table register.

The display can be configured to show the table output by changing the appropriate Src setting value to Table in the UI submenu of the configuration menu. Likewise, the analog output can be configured to follow the table output by changing its Src setting to Table.

Output

A five-point example set-up is in Figure 8. When

the input value is 90, the output will be 54.

Teaching

Figure 8

100

Input

In addition to manually entering the X and Y values, the X values can be taught. It means that the current input value is copied to one of the X values. Then the corresponding Y value can be set, and the table function output will be the Y value entered always with this input.

An example: A three point teaching of a potentiometer. Set Pts to value of 3. Turn the potentiometer to the first position (that gives the smallest ohms). Give a Lock command for the X1 value, and the device will copy the current input value to it. Enter the engineering value (e.g. potentiometer angle) in Y1. Move the potentiometer to the middle teaching position, and repeat the operations using X2 and Y2. Repeat once more for the third teaching position.

The

Lock command

is given in Mekuwin by clicking the L button next to the value. On the integral display, browse to the item (X1-X10) but do not start editing – nothing should be blinking. Now press the joystick one second, and a pop-up menu appears. Select Lock.

ELO PROGRAM

ELo is a simple scripting language developed by Nokeval. Small programs can be used to extend the capabilities offered by the other functions. ELo can do basic calculation, conditional execution and timing. The program can handle both floating point values and binary values. The ELo program is interpreted, not compiled.

The program can be entered with Mekuwin software. It is entered in the

Program

item in the Math submenu of the configuration menu. The maximum length is 320 characters, each line feed counted as one character.

Registers

ELo program can read all the registers (see Registers on page 7), but typically writes the F1 to F12 registers

only. It is possible to write some other registers too (e.g. a setpoint register). The F registers are initialized to 0 at power-up.

There are two ways to reference a register. The most readable method is to use the name of the register directly, e.g. In or F1. The case of the register name is important: “in” or “f1” do not do the job. Since the program is interpreted, this method limits the execution speed of the program, which in most cases is not a matter.

The more effective way is to write @ and the number of the register, e.g. @1 is the In register and @8 is F1.

A special register Intv or @0 contains the time interval between the beginning of the previous and the current execution of the ELo program in seconds. It can be used to count time. Writing F1+=Intv will make F1 to count seconds (with a resolution of dozens of milliseconds).

It is important to remember that a register owned by another module (e.g. the In register) may be updated during the ELo execution. Reading the register value may yield a different value than at the previous time.

However, the F registers are double-buffered: When the ELo program writes to them, the values are stored in a temporary buffer, and when the program execution ends, these values are copied to the public F registers available to the other modules.

Not-a-number

Not-a-number or NaN is a special value for a floating point register to indicate an erroneous value. The ELo program can set any F register to NaN, and test any register against NaN.

The NaN value is used by the other modules of this transmitter too: the In register will contain NaN in case of sensor fault. If the analog output is configured to follow a register that has a NaN value, the output will indicate fault as defined by its Break setting.

Any calculation involving a NaN will yield NaN, e.g. NaN/2 will result in NaN.

Trigger

The

Trigger

setting defines when the program execution is launched. One register can be selected as the trigger. Whenever the value of that register is updated, the program will execute. If the program is mainly processing the input readings, a natural choice as a trigger is the In register.

If the trigger register is not updated for a long time, the program will be executed approximately 1 second after the previous execution finished.

It can’t be guaranteed that the program execution is finished before the trigger is tripped again. In this case the program will re-execute almost immediately when the previous execution is finished.

If the Trigger setting is set to None, the program is re-executed approximately 200 milliseconds after the end of the previous execution.

Limitation

The program execution is limited to 200 operations (one line counted as one operation) in order to prevent total lock-up in a case of e.g. an eternal loop.

Program structure

The program consists of lines. Every line has one simple command. The command can change a register or cause a conditional or unconditional jump inside the program.

Math commands

Each row can contain only one command, i.e. it is not allowed to write dest=src1+src2+src3.

dest=src

Copies a value from src to dest. Src can be a register reference or a constant. E.g.

dest=NaN dest=src1+src2

F1=3.14 will place a value 3.14 in register F1.

Puts a not-a-number value to dest.

Sums src1 and src2 value and places the result in dest register. E.g. F1=In+10 will add register In contents to a value of 10 and place the result in register F1.

dest=src1-src2 dest=src1*src2

Subtracts.

Multiplies.

dest=src1/src2

Divides.

dest=src1**src2

Src1 raised to power of src2.

dest=src1**0.5 dest=src1&src2 dest=src1|src2 dest=src1^src2 dest+=src destX=src

Square root.

Bitwise AND. If applied to a floating-point value, it is first converted to an 8-bit integer.

Bitwise OR.

Exclusive OR.

Sums src and dest and places the result in dest. Exactly same as writing dest=dest+src.

The same for other operators, e.g. F1*=10.

Jumps and conditional jumps

?lines x==y?lines x!=y?lines x<y?lines x<=y?lines x>=y?lines x>y?lines x==NaN?lines x!=NaN?lines

Jumps given number of lines forward (+) or backward (-). E.g. ?-2 will execute the command that is two lines above this line. ?2 will skip the next line. ?0 creates an eternal loop. Jumping outside of the program is allowed: ?99 will exit the program.

Jumps given number of lines if x equals y. E.g. F2==0?3

Jumps if x is not equal to y.

Jumps if x is less than y.

Jumps if x is less or equal to y.

Jumps if x is greater or equal to y.

Jumps if x is greater than y.

Jumps if x is not-a-number

Jumps if x is not not-a-number

References

1.23

@F1

Decimal constant. Allowed characters plus, minus, point, digits 0…9.

Errors

Whenever an error occurs in the execution, the Math error diagnostic message will be activated. The error number and error line can be checked in the configuration menu items Math/Error and Math/ErrLine correspondingly. The error numbers are:

No errors.

Too long operand or operator.

Unknown operator.

Execution exceeds 200 operations.

Failed to write a register.

Illegal register reference. Please remember that the references are case-sensitive.

Examples

Peak hold

Remembers the highest value of the In register and provides the result in F1 register. The digital input can be used to reset the hold.

F2=In

F1>=F2?2

F1=F2

DigiIn==0?2

F1=F2

Take a working copy in F2 because the In register can change anytime

If current hold (F1) is greater than current input (F2), skip the next command

Copy the current input to current hold – we have a new peak

If digital input is not active, skip the next line

Digital input is active – reset the hold by copying the current input to it

Totalizer

Increases one register at the rate defined by the current input. This example does not have a reset.

F2=In*Intv

F1+=F2

Current input multiplied by the time interval from the previous execution

Increase the totalizer register

Slow scanning display

The standard options in the user interface settings allow “scanning” the display, i.e. automatically changing the current screen every 1 or 2 seconds. This example makes a 4 second scanning.

F1+=Intv

F1<=4?6

F1=0

Screen==4?3

Screen+=1

Screen=1

Increase F1 by the time interval from previous execution

Still less than 4 seconds – skip all the next rows

Reset the timing

If in the last screen, jump to the code that will handle that situation

Advance to the next screen

Jump over the next line

Go to the first screen

Polynomial

Calculates y = 30 x^3 – 20 x^2 + 10 x – 5. Input: In register copied to F2. Output: F1.

F2=In

F1=30

F1*=F2

F1+=-20

F1*=F2

F1+=10

F1*=F2

F1+=-5

Take a working copy, because In register can change anytime

Highest coefficient

Multiplied by x

Second coefficient

Etc

SERIAL BUS RS-485

The transmitter can be connected to an RS-485 bus. The bus allows several slaves and one master. This is a slave device.

Connecting

The RS-485 bus is connected to connector B. The bus consists of a twisted full-duplex

(bidirectional) data pair and a common wire. The cable should be shielded, the shield earthed at one point. The nominal impedance should be approx. 100-120 Ω.

The polarity of the data pair is important. Modbus specifications call the positive idling line

D1, but it is also commonly known on names +, B, and A. Correspondingly the negative idling line is -, A, or B. The wires are never crossed.

If the bus is long (say more than 100 m), it is recommended to terminate the first and last device on the bus. Some devices provide internal means for it, but this transmitter does not. An external 100…120 ohm resistor can be connected between the data wires.

B 4 3 2 1

Figure 9

The bus needs one device that gives a small voltage (0.2 V or more) between the data wires when no device is transmitting on the bus. This is called polarizing, biasing, or fail-safing. The master device is usually the natural choice for this. Using a multimeter to measure the equal value and polarity of the idle voltage at each bus device is a good way to check the integrity of the wiring.

Settings

The serial bus settings are collected in the Serial submenu in the configuration menu.

This device supports two protocols: Nokeval SCL and Modbus RTU. The selection is made with the

Protocol

setting. More about the protocols in chapters SCL protocol, page 28, and Modbus protocol, page 29.

Since several devices can be attached to a bus, each device needs to be configured to a different

Address

Legal addresses with Nokeval SCL are 0…123. Modbus allows addresses 1…247.

This device supports common

baud

rates 300…115200 bits/s.

Nokeval SCL uses always 8N1

parity

. Modbus RTU allows using 8E1 (recommended), 8O1, 8N2 and 8N1.

With Modbus, the registers can be read as 16-bit integers or 32-bit floating point numbers. This transmitter performs all internal calculations with 32-bit floating point numbers. When they are converted to a 16-bit integer, they can be scaled with the

Dec

setting to better utilize the limited resolution of the integer. If Dec=0, the value is just rounded to an integer. If Dec=1, the value is multiplied by 10 before conversion. With Dec=2, the value is multiplied by 100, etc. If measuring a temperature that never exceeds 327 °C, it is advisable to set

Dec=2 to get maximum resolution, because the signed 16-bit integer can have a value of -32767 to +32767.

Integer value of -32768 (8000 in hexadecimal) is used to indicate invalid value.

The Conf setting defines if the configuration settings are allowed to be changed by the Modbus Write Holding register command. It also controls resetting the device with the Nopsa command.

SCL PROTOCOL

A full specification of the Nokeval SCL protocol can be downloaded from Nokeval WWW site . Shortly, the command frame consists of address byte (bus address+128), human-readable command, ETX character (ASCII

3), and XOR checksum of all bytes excluding the address byte. A normal response consists of ACK (ASCII 6), human-readable response, ETX, and XOR checksum of all the bytes including ACK. An error response is similar but ACK is replaced by NAK (ASCII 21). The parity is 8N1.

In this device, SCL protocol allows querying the register values, including the latest input reading, configuring with the Mekuwin program, and many operations with the Nopsa language, see page 33.

Command set

TYPE ?

Returns the model name and the firmware version of this device space-separated: RMC685 V1.2. The RTC685 will return RMC685 as its model name.

SN ?

Returns the serial number, e.g. A123456.

MEA CH <ch> ?

Returns the value of register ch. E.g. MEA CH 1 ?. The registers are numbered as in table on page 7. Every

The response may contain digits 0-9, minus sign, and a decimal point. The scientific representation 1.00E-3 is not used. In case of a fault (NaN), the response consists of dashes only -----.

MEA SCAN <first> <last>

Returns the values of registers first to last separated with a space. E.g. MEA SCAN 1 3 will return the values of registers 1, 2, and 3, i.e. In, CJ, and DigiIn. An example response: 25.6667 29.1240 0.

If requesting more registers than the serial buffer can hold, less registers are returned.

DI CH 1 ?

Returns the state of the digital input: 0 or 1 (pulled low).

OUT CH <ch> <value>

Writes a value to one of the Ser registers. OUT CH 1 100 will write a value of 100 to Ser1. An analog output can be configured to follow a Ser register, or the value may be used in the ELo program. The Ser registers are reset at power-up.

OUT SCAN <first> <last> <value1> <value2>…

Writes a value to several Ser registers. E.g. OUT SCAN 1 2 100 200.

N <hexadecimal data>

Encapsulating a Nopsa command in SCL. The Nopsa command is converted to hexadecimal characters without spaces. E.g. querying the serial number: N 0102. The device responds with hexadecimal characters carrying a

Nopsa response. See page 33.

MN <hexadecimal data>

A legacy command for encapsulating Meku configuration commands in SCL protocol. Using Nopsa is recommended.

MODBUS PROTOCOL

The maximum frame length is 100 bytes.

Supported commands

3 Read Holding Registers

Allows reading the configuration settings. Also allows reading the Input registers. The register usage is specified in a table below.

4 Read Input Registers

Allows reading the input reading and all other variable value registers.

6 Write Single Register

Changing the configuration settings and the Ser registers. When changing the configuration settings, the settings are automatically saved to EEPROM. The Ser registers are never saved in EEPROM, but they are zeroed at power-up.

If changing the Serial settings, the changes will not affect until the transmitter is powered down. This is to prevent breaking the connection while making the changes.

It is not possible to change the configuration if the Conf setting is disabled in the Serial settings.

16 Write Multiple registers

Like Write Single Register but allows writing several registers at once.

17 Report Slave ID

Returns information about this device. The run indicator is always 0xFF. The free bytes contain a spaceseparated string consisting of device type, firmware version, and serial number, e.g. RMC685 V1.2 A012345.

The model RTC685 will return RMC685 as its model.

43 14 Read Device Identification

Returns information of this device according to Modbus specifications. Supports only the Basic Device

Information and the stream access.

109 Meku

A legacy command for Meku configuration language used by the Mekuwin software.

110 Nopsa

Encapsulating Nopsa commands in Modbus. The PDU consists of Modbus function code 110, a length byte, and the Nopsa command. The length byte indicates the Nopsa command length. The response format is the same. The supported Nopsa commands are listed on page 33.

Data types

Name

BOOL

BYTE

WORD

ENUM

CODE

FLOAT

Size (regs) Description

Off/on value. 0=False, 1=True.

One byte value. Only the lower (rightmost) byte of the Modbus register is used.

16-bit value.

Option list setting. The options are listed in tables.

Password 12 bits. 0=not used.

32-bit floating point number IEEE 754. Least significant word first (LSWF, little-

STRINGZ

REF

Any

2 endian).

String. If the string occupies less space than reserved, it will be terminated by a zero byte.

Reference to a register or to Meku. The first word defines the space:

0x0000=None, 0xFF02=Meku, 0xFF03=Register. In a Meku reference, the second word defines the Meku item number. In a Register reference, the second word

defines the register (see page 7), indexed from 0.

Within one Modbus register, the data is represented the most significant byte first (MSBF) as required by the

Modbus standard.

Holding registers

The table shows register addresses (address transferred in the PDU + 1). To get a Modicon style address, add

40000 to the table address.

Address

1…2

3…4

Name

Ser1

Ser2

1001

1002

2001

2002…

Ser1

Ser2

Conf\UI\Screens\Count

Conf\UI\Screens\Scan

2003…2004 Conf\UI\Screens\1\Upper\Src

2005

Conf\UI\Screens\1\Upper\Dec

2006…2009 Conf\UI\Screens\1\Upper\Text

2010…2011 Conf\UI\Screens\1\Lower\Src

2012

Conf\UI\Screens\1\Lower\Dec

2013…2016 Conf\UI\Screens\1\Lower\Text

2017…2018 Conf\UI\Screens\2\Upper\Src

2055…2058 Conf\UI\Screens\4\Lower\Text

2059…2060 Conf\UI\Setpoints\1\Min

2061…2062 Conf\UI\Setpoints\1\Max

2063…2064 Conf\UI\Setpoints\2\Min

2065…2066 Conf\UI\Setpoints\2\Max

2067

2068

Conf\UI\Passwords\Conf

Conf\UI\Passwords\Oper

2069

Conf\Input\Sensor

2070…2071 Conf\Input\R0

2072

Conf\Input\Wires

2073

2074

2075

2076

Conf\Input\Unit

Conf\Input\Supply

Conf\Input\Pullup

Conf\Input\Speed

2077

Conf\Input\MovAvg

2078…2079 Conf\Input\Lopass

2080

Conf\Input\Pts

2081…2082 Conf\Input\Mea1

2083…2084 Conf\Input\Sca1

2085…2086 Conf\Input\Mea2

2087…2088 Conf\Input\Sca2

2089…2090 Conf\Input\Lo

2091…2092 Conf\Input\Hi

2093…2094 Conf\Table\Src

2095

Conf\Table\Pts

2096…2097 Conf\Table\X1

Type

FLOAT

Values

WORD

BYTE Unsigned 1…4

ENUM See table E1

REF

BYTE Signed -4…5

STRINGZ Len=8

REF

BYTE Signed -4…5

STRINGZ Len=8

REF

STRINGZ Len=8

FLOAT Signed

CODE

ENUM See table E2

FLOAT Unsigned

ENUM See table E3

ENUM See table E4

BOOL

ENUM See table E5

BYTE Unsigned 1…20

FLOAT Unsigned

BYTE Unsigned 0…2

FLOAT Signed

REF

BYTE Unsigned 0…10

FLOAT Signed

2098…2099 Conf\Table\Y1

2100…2101 Conf\Table\X2

2134…2135 Conf\Table\Y10

2136…2295 Conf\Math\Program

2296…2297 Conf\Math\Trigger

2298

2299

Conf\Math\Error

Conf\Math\ErrLine

2300…2301 Conf\Output\Src

2302

Conf\Output\Range

2303…2304 Conf\Output\Lo

2305…2306 Conf\Output\Hi

2307…2308 Conf\Output\Rdg1

2309…2310 Conf\Output\Out1

2311…2312 Conf\Output\Rdg2

2313…2314 Conf\Output\Out2

2315

Conf\Output\Limit

2316

2317

2318

2319

2320

2321

Conf\Output\Break

Conf\Serial\Protocol

Conf\Serial\Address

Conf\Serial\Baud

Conf\Serial\Parity

Conf\Serial\Dec

FLOAT

BYTE

REF

Signed

FLOAT Signed

STRINGZ Len=320

REF

Unsigned 0…255

ENUM See table E6

FLOAT Signed

BOOL

ENUM See table E7

ENUM See table E8

BYTE

2322

Conf\Serial\Conf

2323…2324 Conf\Agents\1\Src

2325…2326 Conf\Agents\1\Dest

2327…2328 Conf\Agents\2\Src

BOOL

REF

2329…2330 Conf\Agents\2\Dest

5001…5043 Input registers 1…43 shadowed

REF

6001…6023 Input registers 1001…1023 shadowed WORD

Unsigned 0…255

ENUM See table E9

ENUM See table E10

Signed 0…3

Input registers

The table shows register addresses (address transferred in the PDU + 1). To get a Modicon style address, add

30000 to the table address.

Address Name Type Values

1…2

3…4

FLOAT Signed

DigiIn BOOL 0…1

Integer address

1001

1002

1003

6…7

8…9

Table FLOAT Signed

Out FLOAT Signed

10…11

Setp1 FLOAT Signed

12…13

Setp2 FLOAT Signed

14…15

16…17

36…37

F12

FLOAT Signed

38…39

Ser1 FLOAT Signed

40…41

Ser2 FLOAT Signed

Screen BYTE

Keys BYTE

1020

1021

Unsigned 1…4 1022

Bits 0…31 1023

1004

1005

1006

1007

1008

1009

1019

Registers 1001…1023 contain the registers as 16-bit integers, multiplied by a coefficient before conversion.

The coefficient is 10

Dec

, where Dec is the setting Serial/Dec.

Enum values

Table E1

Value Scan

Manual

Spring

Table E2

Value Sensor

Off

9mV

70mV

290mV

1100mV

±1100mV

11V

0-10V

0.18mA

1.5mA

24mA

0-20mA

4-20mA

75ohm

600ohm

TcB

TcC

TcD

TcE

TcG

3000ohm

10000ohm

KTY83

NTCLE3977

TcJ

TcK

TcL

TcN

TcR

TcS

TcT

Table E3

Value Wires

Table E4

Value Unit

°C

°F

Table E5

Value Speed

Slow

Normal

Brisk

Fast

Super

Table E6

Value Range

0-20mA

4-20mA mA

0-10V

Table E7

Value Break

Min

Max

Table E8

Value Protocol

SCL

Modbus

Table E9

Value Baud

300

600

1200

2400

4800

9600

19200

38400

57600

115200

230400

Table E10

Value Parity

(7E1)

8N1

8E1

8O1

8N2

NOPSA LANGUAGE

Nopsa is a protocol-independent machine-to-machine language specified by Nokeval. The commands are described in detail in a separate Nopsa specification.

2/0

2/1

2/2

2/3

4/0

4/1

4/2

4/3

4/4

4/5

7/32

7/33

Command number

1/0

1/1

1/2

1/3

1/4

1/16

1/32

1/33

Name

Type

Version

Serial number

Description

Serial buffer size

Reset

Meku

Go to bootloader

Get value

Get info

Put value

Put info

Ring buffer info

Move to oldest

Move to newest

Read by index

RING BUFFER

The ring buffer enables reading the input readings sample by sample instead of querying the latest value with arbitrary interval. This is a good way to read when targeting for a maximum update rate. The

Conf/Input/Speed setting defines the rate at which new samples are put in the ring buffer. It is not possible to use the ring buffer to store other registers than In.

The ring buffer size is 40 entries.

Since this device does not have a real-time clock, the timestamp is given relative to the moment of processing the read command, expressed in milliseconds. The id field is always 0, referring to the first register, “In”. Data is always stored as a 32-bit floating point number.

AGENTS

The configuration menu contains dozens of settings that define the behavior of this device. They are usually changed very seldom, mainly when setting up a new device. On the other hand, the registers contain continuously varying values, e.g. the input reading, the ELo program variables, and the table function output.

An agent is a bridge between these. Once configured, it reads one register and copies its value to a certain configuration setting. This device has two agents. Each of them has two configuration settings.

Src

defines the register to read, and

Dest

is used to select the configuration setting to write to. To disable an agent, set either or both of the settings to None.

ELo controlled setting

The ELo program can’t directly access a configuration setting. With an agent, the ELo program can alter a setting. An example: The user wants to enable or disable the lowpass filter with an external switch. The desired lowpass time constant is 2 seconds. Write an ELo program:

F1=DigiIn*2 Since DigiIn is either 0 or 1, the result is 0 or 2.

Then configure an agent to copy F1 to the lowpass filter setting:

Agents/1/Src

Agents/1/Dest

Reg/F1

Meku/Conf/Input/Lopass

Setpoint controlled setting

If a certain configuration setting is often needed to be changed, a quick access for it can be arranged using an agent and a setpoint. An example of quick access to the analog output high end scaling. Set up a setpoint in

UI/Setpoints/1 menu under the configuration menu. Define suitable minimum and maximum values e.g. 50 to

500. Call the setpoint to a suitable screen by setting one of its Src settings to Setp1. An example:

UI/Screens/2/Upper/Src None

UI/Screens/2/Upper/Text High

UI/Screens/2/Lower/Src Reg/Setp1

UI/Screens/2/Lower/Dec 1

UI/Screens/2/Lower/Text

Set up the agent to copy Reg/Setp1 to Meku/Conf/Output/Hi.

HIGH

50.0

In the normal state, select screen 2 and press *. The lower row starts to blink, and the value can be adjusted.

More about the setpoints on page 22.

Serial controlled setting

There are two registers that can be controlled by the serial bus: Ser1 and Ser2. Just like in the previous examples, an agent can be configured to copy a value from Ser1 or Ser2 to a configuration setting. The Ser registers will be reset to zero at power-off.

Limitations

The agent works most fluently on floating point numbers. It is also possible to write to an integer type configuration setting e.g. Screens/1/Upper/Dec or Input/MovAvg. Negative values may not work properly.

Further it is also possible to write to an options type setting like Serial/Baud, but the value must be an index to the option beginning from 0. E.g. to select 9600 baud, write a value of 5.

SPECIFICATIONS

Environmental

Operating temp

Storage temp

Humidity

Altitude

Protection

Pollution degree

Dimensions

Weight

Power supply

Voltage

Typical current

24 V DC ±15%

25 mA without mA output nor transmitter supply

120 mA Max current

Galvanic isolation

Description

Isolation voltage

-20…+60 °C (the LCD will be readable at 0…50 °C)

-20…+60 °C

10…90 %Rh noncondensing

Max 2000 m

IP 20

23×110×117 WHD

130 g

These groups are isolated from each other:

1) Power supply.

2) Input.

3) Analog output, RS-485, digital input, and programming connector share a common ground.

50 V AC or 120 V DC continuous, 500 V transient

Input

General

Update rates

Filters

1.9, 7.8, 15.6, and 50 Hz.

Specifications valid for

1.9 and 7.8 Hz rates.

1 to 20 samples moving average and 0 to 60 seconds 1 st

degree lowpass

Overvoltage protect ±18 V DC

Cable length < 30 m

Power-up time 1 s to first reading

Warm-up time 10 min to full accuracy

Pt100 (α=0.00385)

Connection methods 2, 3, or 4 wires

Range -200…+700 °C

Wire resistance

Accuracy 3-wire

Max 10 Ω

0.05% rdg + 0.2 °C at 25

Accuracy 4-wire

Thermal drift

Noise (unfiltered)

Sensor current

°C env

0.05% rdg + 0.1 °C at 25

°C env

0.01 °C/°C ref 25 °C env

3-wire: typ 0.02 °C rms,

4-wire: typ 0.01 °C rms approx. 250 µA DC continuous

Pt1000

Range

Accuracy

Ni100

Range

Accuracy

-200…+700 °C

0.1% rdg + 0.2 °C

-60…+180 °C

0.05% rdg + 0.2 °C

Cu10

Range

Accuracy

KTY83

Range

-200…+260 °C

1 °C

-55…+175 °C

NTCLE3977 Vishay NTCLE β=3977

Range -40…+150 °C

Ohm (resistance, potentiometer)

Ranges

Accuracy

0-75, 0-600, 0-3000, and

0-10000 Ω

0.05% rdg + 0.5 Ω

Thermocouples

Type

Range °C

400…1700

0…2300

-100…900

1000…2300

-160…950

-150…1370

-150…900

0…1300

Lin.error °C

0.3

0.5

0.2

0.5

0.1

Thermal drift

Accuracy

0…1700

-200…400

0.5

< 0.02 °C/°C ref 25 °C env

0.05% rdg + 0.6 °C + lin.error + thermal drift typ 0.03 °C rms Noise

Millivolts

Ranges

Accuracy

Offset thermal drift

Gain thermal drift

Noise

±9, ±70, -70…290, ±1100 mV

0.05% rdg + 0.01 mV at

25 °C

< 200 nV/°C

< 50 ppm/°C

9 mV range: typ 500 nV rms

> 10 MΩ | 250 nF Input impedance

Volts

Range

Accuracy

Gain thermal drift

Noise

Input impedance

Milliamperes

Ranges

Accuracy

-11…11 V

0.05% rdg + 0.001 V at 25

°C

< 50 ppm/°C ref 25 °C typ 200 µV rms

> 10 MΩ | 150 nF

Gain thermal drift

Noise

Load

Transmitter supply

Digital input

±0.18, ±1.5, and ±24 mA

0.05% rdg + 0.004 mA at

25 °C

< 50 ppm/°C ref 25 °C typ 300 nA rms

50…80 Ω

15 V ±10%, max 50 mA

Input type

Active state

Passive state

Cable length

Table function

For NPN output or switch

(internal pull-up 10 kΩ to

3.3 V)

-3 … 0.7 V

2.6 … 5.5 V

< 3 m

Number of points

Interpolation

2 to 10

Linear

Analog output

General

Response speed 0.5 s fully settled

mA signal

Standard ranges

Custom ranges

Accuracy

0-20 mA, 4-20 mA

Any within 0…22 mA

0.008 mA at 25 °C

Gain thermal drift < 50 ppm/°C

Sensor break indication 0 mA, 3.5mA, or 22.5 mA

Max load 600 Ω

V signal

Standard range 0-10 V

Custom ranges

Accuracy

Any within 0…10 V

0.005 V at 25 °C

Gain thermal drift < 50 ppm/°C

Sensor break indication 0 or 11 V

Max load 5 kΩ

RS-485 bus

Protocols

Baud rates

Modbus parity

Min response time

Typ response time

Max response time

Nokeval SCL and Modbus

RTU

1200, 2400, 4800, 9600,

19200, 38400, 57600,

115200 bits/s

8E1, 8O1, 8N2, 8N1

3.5 characters or 1.7 ms whichever greater

Querying one reading: the same as Min response time.

15 ms when reading input register 1 or 1001.

Much longer when operating with holding registers.

Regulations

EMC immunity

EMC emissions

EN 61326

EN 61326 class A

Hello! I am an AI chatbot specifically trained to assist you with the Nokeval RTC685 User Manual. I have thoroughly reviewed the document and can help you locate the exact information you need or explain the content in clear and simple terms. Whether you’re looking for guidance on specific features, troubleshooting steps, or general usage, feel free to ask your questions. The more details you provide about your concerns or needs, the more accurately and effectively I can assist you!

Assistant typing

Assistant terminated

Nokeval

User Manual

CONTENTS

INTRODUCTION

WARNINGS

TRADEMARKS

MANUFACTURER

QUICK SET-UP

Connections overview

Quick configuration

INSTALLING

Mounting

Jumpers

Connections

Power supply

MAINTENANCE

Cleaning

Recalibration

Calibration certificate

OPERATION

Registers

Self-diagnostics messages

CONFIGURING

With the integral display (RMC685 only)

With a programming cable

Over the serial bus

Configuration menu

INPUT

General

RTD sensors including Pt100

Connections

Settings

Thermocouples

Connections

Settings

mA input

Connections

Settings

Fault detection

Voltage inputs

Connections

Settings

Resistance input and potentiometer

Common input settings

Sensor fault detection

Measurement speed

Filters

Advanced scaling

Sensor error correction

Potentiometer teaching

DIGITAL INPUT

ANALOG OUTPUT

Connections

Source

Range and scaling

Limit and break

USER INTERFACE

Configuration state

Entering

Navigating

Editing floating point values

Editing integer values

Editing options

Register and Meku references

Entering a password

Editing text

Exiting

Monitoring and simulating

Self-diagnostics

LEDs

Normal state and the screens

Default screen

Switching among the screens

Defining a screen

Setpoints

TABLE FUNCTION

Teaching

ELO PROGRAM

Registers

Not-a-number