Comet H5421 User manual

CO2concentration, temperature, humidity
and other calculated humidity variables regulator
with RS485 serial output
H5421
H5424
H6420
H6421
Instruction Manual

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Table of content
1. GENERAL DESCRIPTION......................................................................................................4
2. REGULATOR MOUNTING AND CONNECTION...............................................................4
3. DIMENSIONS.............................................................................................................................5
4. TYPICAL APPLICATION WIRING, CONNECTION OF TERMINALS.........................8
5. DESCRIPTION OF DEVICE FUNCTION AND SETTING.................................................9
5.1. DEVICE SETTING FROM THE MANUFACTURER ...................................................................................... 9
5.2. RELAY OUTPUTS ................................................................................................................................... 9
5.3. CARBON DIOXIDE CONCENTRATION MEASUREMENT.......................................................................... 10
5.4. ACTUAL REGULATOR PRESET ............................................................................................................. 10
5.4.1. Value assigned to output relay......................................................................................................................10
5.4.2. When close output relay................................................................................................................................11
5.4.3. Regulator address setting..............................................................................................................................12
5.5. REGULATOR SETTING CHANGE ........................................................................................................... 12
5.5.1. Setting with PC and TSensor software..........................................................................................................12
5.5.2. Setting with using regulator keys..................................................................................................................12
5.5.3. Setting with using of Modbus communication protocol ................................................................................13
5.6. EXTENDED SETTING MODE.................................................................................................................. 13
5.7. RESTORE TO „FACTORY DEFAULT“.................................................................................................... 17
6. DESCRIPTION OF COMMUNICATION PROTOCOLS..................................................18
6.1. MODBUS RTU..................................................................................................................................... 18
6.1.1. Supported functions ......................................................................................................................................18
6.1.2. Jumper ..........................................................................................................................................................18
6.1.3. Modbus registers of the regulator.................................................................................................................19
6.1.4. Far controlling of output relays status..........................................................................................................19
6.1.5. Output relay alarm condition configuration with using of Modbus communication protocol......................20
6.2. PROTOCOL COMPATIBLE WITH ADVANTECH-ADAM STANDARD...................................................... 21
6.2.1. Jumper ..........................................................................................................................................................22
7. ERROR STATES OF THE DEVICE.....................................................................................23
8. READINGS ON LCD DISPLAY ............................................................................................24
9. PREVENTIVE MAINTENANCE AND CALIBRATION ...................................................24
10. TECHNICAL SPECIFICATION............................................................................................24
10.1. TECHNICAL PARAMETERS................................................................................................................... 24
10.1.1. Common parameters.....................................................................................................................................24
10.1.2. H5421 - CO2regulator .................................................................................................................................25
10.1.3. H5424 - CO2regulator .................................................................................................................................25
10.1.4. H6420 - temperature, relative humidity and CO2regulator.........................................................................25
10.1.5. H6421 - temperature, relative humidity and CO2regulator.........................................................................26
10.1.6. Relative humidity and temperature restriction..............................................................................................26
10.1.7. Value computed from measured relative humidity and temperature ............................................................27
10.2. OPERATING CONDITIONS .................................................................................................................... 28
10.3. END OF OPERATION............................................................................................................................. 29
10.4. TECHNICAL SUPPORT AND SERVICE.................................................................................................... 29
11. APPENDIX A............................................................................................................................29
12. APPENDIX B ............................................................................................................................30

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General safety rules
The following summary is designed to prevent injury hazards or device damage. Operate
the instrument in accordance with this manual to prevent electric trauma.
Service should be performed by a qualified person only.
Connect and disconnect correctly. Do not connect and disconnect a lead-in cables if the device is
under electric voltage.
Do not use the instrument without the cover.
Do not use the instrument, if it does not work correctly. If the instrument seems not to work
correctly, have it checked by a qualified service person.
Do not use the instrument in an explosive environment.
Read instruction manual before the first device connection, please.
Models marked HxxxxZ are non-standard versions of the devices. Description is not included in this
manual.
Copyright: COMET SYSTEM, Ltd. It is prohibited to copy and edit this instruction manual
and make any changes at all without explicit agreement of COMET SYSTEM, Ltd. All rights
reserved.
COMET SYSTEM, Ltd makes constant development and improvement of all its products. That is
why it reserves the right to make any technical changes on the device/product without previous notice.
Manufacturer is not responsible for damages caused by using the device in conflict with this manual.
To damages caused by using the device in conflict with this manual cannot be provided free repairs
during the warranty period.
Contact the manufacturer of this device:
COMET SYSTEM, s.r.o.
Bezrucova 2901
756 61 Roznov pod Radhostem
Czech Republic
www.cometsystem.com

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1. General description
The regulators are designed for online measurement of temperature (°C or °F), relative humidity
and carbon dioxide concentration of air without aggressive ingredients. Measured temperature and
relative humidity are recomputed to following humidity expression: dew point temperature, absolute
humidity, specific humidity, mixing ratio and specific enthalpy.
The regulators are designed to be operated in a chemically non-aggressive environment.
Type
Temperature
Humidity
CO2
Computed value
H5421
-
-
✓
-
H5424
-
-
✓
-
H6420
✓
✓
✓
✓
H6421
✓
✓
✓
✓
The device is equipped with two relay outputs for alarming or controlling of external devices. It is
possible to assign any input value to each relay, to set comparing limit, delay, hysteresis, acoustic
alarm or change its status by far control with using of Modbus communication protocol.The device
communicates via link RS485.
Supported communication protocols are Modbus RTU and protocol compatible with standard
Advantech-ADAM. Devices are preset from manufacturer to Modbus RTU communication protocol.
If you would like to use different communication protocol then Modbus RTU, it is necessary preset
them –see latter. Measured and computed values are displayed on dual line LCD. It is also possible
to display both readings with cyclic overwriting in 4 seconds interval. Display can be also switched
OFF totally. On the left LCD side there are placed three LEDs for CO2zone level indication.
2. Regulator mounting and connection
Regulators are designed for wall mounting. Device must be mounted on the plane surface to
prevent its deformation. Mounting holes and connection terminals are accessible after demounting of
four screws in the corners of the box and removing the lid. There is recommended to use screws with
half round head with cross-recessed screw ST
3.9 (DIN 7981). External probe for measuring
the concentration of CO2 unpack and connect to
the device.
Lace the lead-in cable with outer diameter
of 3 to 6.5 mm through the glands at the case
wall and connect them according schematic
below. Terminals are self-clamping and can be
opened by a suitable screwdriver. For the
opening, insert the screwdriver to smaller
terminal hole and lever by him. Do not forget to
tighten glands and case lid with inserted packing
after cables connecting. Insert attached plug into
unused cable glands too. Do not connect the
regulator under voltage.
It is not recommended to use the device
H6420 and external RH+T probe of H6421
regulator for long time under condensation
conditions. It could be the cause of water steam

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condensation inside the sensor’s cover into water phase. This liquid phase stays inside sensor’s cover
and can’t escape from the cover easily. It can dramatically increase response time to relative humidity
change. If water condensation occurs for longer time it can cause sensor damage. Similar effect can
occur under water aerosol conditions.
For devices with RS485 output there is recommended to use shielded twisted copper cable,
maximal length 1200m. The cable must be located at indoor rooms. Nominal cable impedance should
be 100 Ω, loop resistance max. 240 Ω, cable capacity max. 65 pF/m. Outside diameter of the cable
for regulator connection must be from 3 to 6.5 mm. Suitable cable is e.g. SYKFY 2x2x0.5 mm2,
where one wire pair serves for device powering and the other pair for communication link.
The cable should be led in one line, i.e. NOT to „tree“ or „star“. Termination resistor should be
located at the end. For short distance other topology is allowed. Terminate the network by a
termination resistor. The value of the resistor is recommended about 120 . For short distance
termination resistor can be left out.
The communication cable must be placed as far as possible from potential interference sources.
Electrical system (wiring) may do only worker with required qualification by rules in operation.
3. Dimensions
H6420

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H5421

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H6421

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H5424
4. Typical application wiring, connection of terminals

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5. Description of device function and setting
Information from regulator is available directly through LCD or you can read them with one of
next communication protocols ( Modbus RTU, Advantech-ADAM ).
5.1. Device setting from the manufacturer
communication protocol: Modbus RTU
regulator address: 1
communication speed: 9600Bd, no parity, 2 stop bits
Value assigned to Relay1 and Relay2: none
Password for setting through keys (PASS): 0000
LCD display: on
value shown at first LCD line: temperature / CO2 - by device type
value shown at second LCD line: relative humidity / dew point temp. - by device type
temperature unit: °C
computed value preset: dew point temperature
relay response for error: stay unchanged at previous condition
acoustic alarm: off
LED indication of CO2concentration up to 1000 ppm lights green LED, between 1000 and
1200 ppm lights yellow LED and over 1200 ppm
lights red LED
altitude: 300 m above sea level at the installation site
5.2. Relay outputs
Regulator is equipped with two relay outputs. It is possible to assign any input or computed value
or “Far condition” (see chapter “Far controlling of output relays status”at page 19) to each relay, to
set comparing alarm limit, if the relay may close if measured value is higher (Hi) or lower (Lo) than
preset limit, delay for while must be preset condition true before relay close its contact and hysteresis
for return to open status. For binary inputs: if it is preset to „HI“ then output relay is closed when
input contact is opened, if it is preset to „Lo“ then output relay is closed when input contact is closed.
Each relay status is indicated with LED diode and shown on LCD with corresponding symbols „
“ or „ “.
Terminal block for connecting the relays is equipped with terminals GND, which are connected
to the power supply of the device (see chapter “Typical application wiring, connection of terminals”).
When you need to use relays to switching the voltage identical with the supply voltage of the device,
you can use jumpers J1 and J2 for interconnection the power supply of the device directly with the
common contacts of the relays. This modification is used in devices with serial number higher
than 16981000 (the wiring diagram of the relay contacts for devices with serial number lower than
16981000 is given in the “Appendix B”).
The devices are equipped with two relays that are not intended for direct switching power circuits
or mains voltage. If necessary, use suitable type of external relay (an example of wiring is given in
the “Appendix A”).

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5.3. Carbon dioxide concentration measurement
A multiple point CO2 and temperature adjustment procedure leads to excellent CO2 measurement
accuracy over the entire temperature working range; this is a must for process control and outdoor
applications. The dual wavelength NDIR CO2 sensing procedure compensates automatically for
ageing effects. The CO2 module is highly resistant to pollution and offers maintenance free operation
and outstanding long term stability. Measured values can be read in „SLOW mode“ (filtered,
averaged) or in „FAST mode“ (current values without averaging). SLOW mode has advantages in
applications like climate control because of filtering short time peaks. As an example exhaled air
from an employee passing the sensor could affect the climate control negatively with a short response
time because the control would trigger a change of the ventilation based on this one-time
measurement. On the contrary in „FAST mode“ no software filter is used for calculating the output
value. This fact adds a noise of typ. ±30ppm which has to be considered in terms of accuracy. Of
principle measurement is the measured value of CO2concentration depends on the value of air
pressure - altitude at the installation site. For this reason, it is suitable for accurate measurement to
set the altitude of the installation site by TSensor software.
After power up there is internal check in progress and takes about 20 s. During this time LCD
display shows (----) instead of CO2concentration value.
Parameter setting description is into chapter “Regulator setting change” at page 12.
5.4. Actual regulator preset
It is possible to display actual regulator preset on its LCD display by
pressing of „▲“ key. If far controlling of output relays status is active (see
chapter 6.1.4 at page 19), then device’s LCD display shows text „bloc“. It
means, device’s keyboard is disabled for time of remote control (setting
change), see chapter 6.1.5 at page 20. LCD shows information about Relay1
and then Relay2 setting step by step. Information about Relay1 are indicated
with symbol „ “, for Relay2 with symbol „ “ (at right top corner of LCD). It
is possible to edit parameters after pressing „SET“ key and entering of correct password „PASS“ –
see chapter “Change of “Password for setting through keys” (PASS)” at page 14. Following examples
are for Relay1 setting, similarly are displayed values for Relay2. Pressing of „ESC“ key ends this
mode and switch to actual value displaying, the same occur if more than 20 s is not pressed any key.
5.4.1. Value assigned to output relay
None, relay is still off
Temperature at °C
Relative humidity
Computed value –dew point temperature
CO2concentration
Far condition 0

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FAR0 –„far condition 0“: after device’s power on the relay is open
FAR1 –„far condition 1“: after device’s power on the relay is close
If “far condition” is assigned to output relay, then there is possible to
change the output relay status by Modbus communication protocol only.
See chapter “Far controlling of output relays status” at page 20.
5.4.2. When close output relay
High limit „HI“ –the relay closes when measured value exceeds preset „high limit” for longer
time than preset „delay time“. Relay goes open when measured value decrease under „high limit“
value minus the „hysteresis” value. See example.
High limit „HI“
Delay [s]
Hysteresis
Low limit „Lo“ –the relay closes when measured value falls below preset „low limit” for longer
time than preset „delay time“. Relay goes open when measured value exceeds „low limit“value plus
the „hysteresis” value. See example.
Low limit „Lo“
Delay [s]
Hysteresis
Far condition 1

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5.4.3. Regulator address setting
Regulator address for preset communication protocol.
RS485 network regulátor address
5.5. Regulator setting change
5.5.1. Setting with PC and TSensor software
User’s software TSensor provides setting of all regulator parameters. The program is available
free to download at web page www.cometsystem.com. Run the TSensor program and follow the
program instructions. Regulator includes hardware write protection of internal setting, new setting is
possible to write only while:
1. during write period press „SET“ key – do requested setting in TSensor software, press „SET“
key on regulator and keep it down, then click on the button „Save Changes“ into TSensor
software and after end of write release „SET“ key, or
2. jumper placed nearby keys is closed (jumper is accessible after demounting of four screws in
the corners of the box and removing the lid ). This jumper is suitable e.g. until device
adjustment is in process and regulator is placed into calibration box and keys are not
accessible. Don’t forget to remove (open) jumper after procedure finish (restore write
protection)
TSensor software supports to make the adjustment of the regulator too. This procedure is described
at file „Calibration manual.pdf“ which is installed commonly with the software.
5.5.2. Setting with using regulator keys
If „Actual regulator preset” is displayed (see chapter ”Actual regulator preset”at page 10), it is
possible to enter into edit mode and edit displayed value by pressing „SET“ key. Then you are asked
for valid password (PASS). You can edit selected value if right password is entered. During value
editing there is range check executed and edited value is still compared with limits for corresponding
value (range). If inserted value is higher or lower then edited number is automatically changed to its
maximum / minimum value –for possible range see chapter „Technical parameters”at page 24.
Value can be changed with using „▲“ and „▼“ keys. Edited value is switched in “round” -9, -8, -7,
…-2, -1, 0, 1, 2, …8, 9. To edit next number digit press „SET“ key, for moving back to previous digit
press „ESC“ key. Edited value is stored by next „SET“ key pressing. It is possible to cancel editing
by pressing „ESC“ key if necessary. If valid password is once inserted right, then there is possible to
edit next items without asking for password insertion again, till “Actual regulator preset” is left (till
actual measured values are shown). With new entering into edit mode it is necessary to enter Password
again. Default password setting is preset from manufacturer to 0000, password change is possible
into „Extended setting”. During edit mode regulator still works and changes are valid immediately
after its storing –it is not necessary to restart regulator.

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5.5.3. Setting with using of Modbus communication protocol
See chapter “Output relay alarm condition configuration with using of Modbus communication
protocol” at page 20.
5.6. Extended setting mode
During regulator operation it is possible to change parameters available through “Actual regulator
preset” only (see chapter 5.4 at page 10). Rest of regulator parameters are available through
“Extended setting mode”. In this mode regulator does NOT communicate, does NOT do any
measurements and does NOT service output relays. To leave this mode press „ESC“ key and
open jumper nearby keys. To enter into Extended setting mode do following steps:
1. disconnect power supply
2. demount four screws in the corners of the box and remove the lid
3. closed jumper placed nearby keys
4. press „▲“ and „▼“ keys together and keep them down
5. connect power supply to regulator –you should see message „SEL“ on the top line of LCD and
on the bottom line you should see number of Firmware version (e.g. 0404)
6. release „▲“ and „▼“ keys – you are into “Extended setting mode” now
Use „▲“ and „▼“ keys to inspect each items. If you want to change some shown item then press
„SET“ key, item starts blink. Now you can edit setting with using „▲“ and „▼“ keys. To store preset
value press „SET“ key. Press „ESC“ key to leave editing (changing) without save – last stored value
is kept.
Acoustic alarm assign to Relay1
acoustic indication of Relay1 is OFF
close of Relay1 contact starts acoustic indication
Acoustic alarm assign to Relay2
acoustic indication of Relay2 is OFF
close of Relay2 contact starts acoustic indication

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Acoustic alarm deactivation
activated acoustic alarm is possible to
deactivate by pressing „ESC“ key
acoustic alarm is still activated for all time and
it is impossible to deactivate it
Relay response for error
Regulator continuously checks its state during operation. In case error of assigned value
measurement is found then output Relay1 (Relay2):
stays unchanged (in previous
status)
Relay1 switch OFF
Relay1 switch On
stays unchanged (in previous
status)
Relay2 switch OFF
Relay2 switch On
Change of “Password for setting through keys” (PASS)
This item shows actual password setting. It is possible to
change it after „SET“ key pressing. It is number from range -
19999 to +19999
Choice of communication protocol
Choice of communication protocol for communication with master device
protocol Modbus
protocol Advantech-Adam
without check sum
protocol Advantech-Adam
with check sum
password setting

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Regulator address setting
Regulator address for preset communication protocol
RS485 network regulator address
Communication speed
Communication speed for preset communication protocol
communication speed setting
Temperature unit choice
It is possible to measure temperature at °C or °F. There is shown preset unit. It is possible to change
it after „SET“ key pressing.
preset to °C
preset to °F
CO2measurement mode selection
This item provides to choice if measured value is displayed and read in “SLOW” or “FAST”
mode. “FAST” mode provides last measured value without averaging; this means that no software
filter is used for calculating the output value. “SLOW” mode provides value averaged from last 11
“FAST” measured values.
averaged value „SLOW“ mode
current value without averaging „FAST“ mode

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CO2zone level indication setup
Whole measuring range can be divided into three areas. Each active
area there is indicated by green, yellow or red LED depends on actual
measured value. It is done by two boundary limits setting. „YELL“
limit sets boundary between green and yellow indication. It means that
if actual measured value is lower than „YELL“ limit, there is green
LED active. If actual measured value is higher than „YELL“ limit, then
there is yellow LED active. Yellow LED lights until actual measured value exceeds „RED“ limit. If
actual value is higher than „RED“ limit, red LED is active. If you don’t want to use this indication
then set “YELL” limit to 0.
„YELLOW“ limit setting
„RED“ limit setting
Show temperature at LCD display
This item provides to choice if actual measured temperature may be displayed at LCD display or
not. It is possible to change it after „SET“ key pressing.
show value on LCD
don’t show value on LCD
Show relative humidity at LCD display
This item provides to choice if actual measured relative humidity may be displayed at LCD display
or not. It is possible to change it after „SET“ key pressing.
show value on LCD
don’t show value on LCD
Show computed value at LCD display
This item provides to choice if actual computed value may be displayed at LCD display or not.
There is shown the name of computed value on the top LCD line –see “Computed value selection“
below. It is possible to change it after „SET“ key pressing.

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show value on LCD
don’t show value on LCD
Show CO2concentration at LCD display
This item provides to choice if CO2value may be displayed at LCD display or not. It is possible
to change it after „SET“ key pressing.
show value on LCD
don’t show value on LCD
Computed value selection
It shows the actually selected computed value name. It is possible to change it after „SET“ key
pressing. There is possible choice one of the following computed values:
dew point temperature
absolute humidity
mixing ratio
specific humidity
specific enthalpy
5.7. Restore to „Factory default“
This item provides regulator restoring to factory setting. Press „SET“ key, select „YES“ and
confirm it by pressing of „SET“ key. It reset regulator parameters to following values:
communication protocol: Modbus RTU
regulator address: 1
communication speed: 9600Bd, no parity, 2 stop bits
value assigned to Relay1 and Relay2: none
password for setting through keys: 0000
display: on

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value shown at first LCD line: temperature / CO2- by device type
value shown at second LCD line: relative humidity / dew point temp. –by device type
temperature unit: °C
computed value preset: dew point temperature
obnova nastavení regulátoru od výrobce
6. Description of communication protocols
Detailed description of each communication protocols including examples of communication is
available into document “Description of communication protocols”, which is available to download
at www.cometsystem.com, see detailed description of appropriate device type. After switching ON
the power of the device it can last up to 3 s before the device starts to communicate and measure !!!
6.1. Modbus RTU
Control units communicate on master-slave principle in half-duplex operation. Only master can
send request and only addressed device responds. During sending of request no other slave station
should respond. During communication, data transfer proceeds in binary format. Each Byte is sent as
eight bit data word in format: 1 start bit, data word 8 bit (LSB first), 2 stop bits
1
, without parity.
Device supports communication speed from 110Bd to 115200Bd.
Sent request and response have syntax: ADDRESS OF DEVICE –FUNCTION –Modbus CRC
6.1.1. Supported functions
03 (0x03): Reading of 16-bit registers (Read Holding Registers)
04 (0x04): Reading of 16-bit input gates (Read Input Registers)
06 (0x06): Setting of one 16-bit register (Write Register)
16 (0x10): Setting of more 16-bit registers (Write Multiple Registers)
6.1.2. Jumper
Jumper (placed nearby keys) is accessible after demounting of four screws in the corners of the
box and removing the lid. If communication protocol Modbus is selected the function of jumper is
as follows:
•Jumper opened –device memory is protected from writing, from device side it is only enabled
to read measured value, writing to memory is disabled (no change of settings is enabled)
•Jumper closed –writing to regulator memory is enabled
1
Device sends two stop bits, for receive one stop bit is enough.

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6.1.3. Modbus registers of the regulator
Variable
Unit
Address
[hex]X
Address
[dec]X
Format
Size
Status
measured temperature
[°C/°F]*
0x0031
49
Int*10
BIN16
R
measured relative humidity
[%]
0x0032
50
Int*10
BIN16
R
computed value*
0x0033
51
Int*10
BIN16
R
CO2 concentration displayed on LCD
ppm
0x0034
52
Int
BIN16
R
Relay1 status [0/1] (Alarm 1)
[-]
0x003B
59
Int
BIN16
R
Relay2 status [0/1](Alarm 2)
[-]
0x003C
60
Int
BIN16
R
CO2 concentration „FAST“ mode
ppm
0x0054
84
Int
BIN16
R
CO2 concentration „SLOW“ mode
ppm
0x0055
85
Int
BIN16
R
status word (described below)
[-]
0x0007
7
Int
BIN16
R
device serial number Hi
[-]
0x1035
4149
BCD
BIN16
R
device serial number Lo
[-]
0x1036
4150
BCD
BIN16
R
firmware version Hi
[-]
0x3001
12289
BCD
BIN16
R
firmware version Lo
[-]
0x3002
12290
BCD
BIN16
R
device address
[-]
0x2001
8193
Int
BIN16
R/W**
communication speed code
[-]
0x2002
8194
Int
BIN16
R/W**
Legend:
•* depends on device setting (by User’s software)
•Int*10 register is in format integer *10 (likewise *100, *1000)
•R register is designed only for deading
•W** register is designed for writing, but direct write is not available, for details see
description of communication protocols
•x at transmit are register addresses indexed from zero - „zero based addressing“.
For example „measured temperature“ with Modbus address 0x31 is physically sent
along data bus as value 0x30. You make sure of correct addressing with the aid of
Master device documentation or experimentally (e.g. for „measured temperature“ try
to use address 0x31 or 0x30).
•Status word: 16b value return, bite description:
Bit0 0/1 jumper open/closed
Bit1 - unused
Bit2 0 always 0
Bit3 0/1 Relay1 open/closed
Bit4 0/1 Relay2 open/closed
Bit5 0/1 internal acoustic alarm status
Bit6 to 15 - unused
Note: In case there is a need for reading of measured values from the device with higher resolution
than one decimal, measured values in device are stored also in „Float“ format, which is not directly
compatible with IEEE754.
6.1.4. Far controlling of output relays status
There is possible to control output relay status (open/close) with using of Modbus communication
protocol. To this function enable, there is necessary to assign one of following options to relay:

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•FAR0 –„Far condition 0“, it means, after power up output relay will be open, or
•FAR1 –„Far condition 1“, it means, after power up output relay will be close.
Then there is possible to change relay status by Modbus communication protocol command by
requested value writing to following addresses:
Function
Address
[hex]X
Address
[dec]X
Description
Status
Far condition for Relay1
0x0042
66
0 - relay open, 1 - relay closed
R/W
Far condition for Relay2
0x0043
67
0 - relay open, 1 - relay closed
R/W
6.1.5. Output relay alarm condition configuration with using of Modbus
communication protocol
2
With Modbus communication protocol there is possible to set regulator’s parameters described at
chapter “Actual regulator preset” at page 10. Follow next steps:
1) To address 0x0044 (68) write value1 –it enables Modbus setting. By the way it blocks
regulator’s keyboard – local keyboard is blocked during remote control setting change.
2) Write the desired settings / changes to the addresses from 0x0045 (69) to 0x004E (78). New
setting can be done simultaneously or each register can be written alone
3) To address 0x004F (79) write value 1. Once this step is done, new setting is physically stored
into device memory (confirm change). Then registers 0x004F (79) and 0x0044 (68) are
automatically cleared (zero). It automatically unlocks the keyboard too.
Whole setting process can be cancelled by writing value 0 to address 0x0044 (68). At this time no
changes are stored and last setting stays valid.
Function
Unit
Address
[hex]X
Address
[dec]X
Description
Status
Modbus
Remote
Control
[-]
0x0044
68
0 ... disable
1 ... enable (for this time device’s keyboard
is blocked, if key is pressed, message
BLOC is shown)
R/W
Value
assigned
to output
Relay1
by
value
0x0045
69
0 ... Off
1 ... temperature
2 ... relative humidity
3 ... atmospheric pressure (CO2
concentration)
4 ... computed value
5 ... unused
6 ... unused
7 ... unused
8 ... Far condition 0
9 ... Far condition 1
R/W
When close
Relay1
[-]
0x0046
70
0 ... alarm occurs, when measured value is
LOWER than preset alarm value
1 ... alarm occurs, when measured value is
HIGHER than preset alarm value
R/W
2
This function is available from firmware version 04.06. If older firmware used, update your firmware or contact device’s
distributor.