Nov. 18
Automatikprodukter
Nitrogen Dioxide, NO
2
Gas Detector - Analogue, Modbus
5
db_nitrogen_transmitter_uk.indd
RNO2
Installation guidelines
Nitrogen dioxide is approximately 1.6 times heavier than air. The
location of the sensor is determined by operating conditions. Thus,
in underground parkings the NO
2
raises to the ceiling with hot
exhaustion gases. Therefore the sensor should be located at 0.2 m
above the floor in order to detect potentially dangerous
concentrations more quickly.
Calibration
RNO2 transmitters have been calibrated by manufacturer with
standard gas mixtures before delivery.
Provided that the sensor is used under moderate conditions, the
recommended interval for field recalibration is 6 months.
Please contact your dealer for more information.
Maintenance
-
Do not perform any maintenance operation with the power
on.
-
Clean the device with soft damp cloth.
-
Do not use any abrasive cleaning agents. Do not immerse the
device into water or any cleaning media.
Delivery set
Transmitter RNO2 (wall mount or duct mount version)
Mounting accessories:
-
4 screws with plastic dowels for wall mount version
-
Rubber flange for duct mount version.
-
Fixing clamp for remote probe version
Databits: 8
Parity: none
Stop bits: 1 or 2
Protocol: Modbus RTU
Supported Modbus functions:
03 - read multiple registers
06 - write single register
Parameter
Permitted values
Default
Supported
baudrates
1200, 2400, 4800,
9600, 19200,
38400, 57600
9600
Data bits
8
8
Parity
none
none
Stop bits
1, 2
1
Protocol
Modbus RTU
03 - read multiple
register
Modbus functions 06 - write single register
Error codes
01. illegal function
02. illegal data address
03. illegal data value
04. slave device failure (details of last error
04 can be read from register 0x0008)
RS485 communication interface
Communication parameters
Addr
Reg/MHR
RW
Description
Supported values (dec)
Default
0x0001
1
R
Hardware version
-
0x0002
2
R
Software version
-
0x0003
3
R
Product serial number
1 . . . 65535
-
0x0004
4
RW
Slave ID (net address)*
1 . . . 247**
1
0x0005
5
RW
Baudrate*
1200, 2400, 4800, 9600, 19200, 38400, 57600
9600
0x0006
6
RW
Response delay ms
1 . . . 255
10
0x0007
7
RW
Stop bits*
1,2
1
0x0008
8
R
Last error code
1 . . . 255
-
0x0011
17
RW
Restarts counter
write ‘42339’ to restrat device (no response will follow)
-
0x0097
151
R
Sensor type code
0 . . . 65535
0
0x0098
152
R
Output units code
0 - ppm, 1 -
0
/
00
, 2 - %
0
* -
** -
*** -
The new value is applied after restart.
Broadcast slave ID 0 can be used to assign a new ID to device with unknown ID. When addressing by ID 0 the device shall be the
only Modbus instrument in the network. The device will not respond to Master command when addressed by ID 0.
This value is dynamic and not kept in EEPROM after restart
Modbus holding registers
Register addresses are shown 0-based, Addr in hexadecimal, Reg in decimal format.
Modbus holding register numbers MHR are shown in decimal 1-based format, and may be addressed either from 00001 or 40001 base.
