Endress+Hauser SpectraSensors J22 TDLAS, Руководство по эксплуатации

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J22 TDLAS Gas Analyzer Operating Instructions
Hauser 57
6 Modbus communication
6.1 Overview of device description files
Current version data for the device.
Firmware version 01.04
• On the title page of the Operating instructions
• Diagnostics → Device information → Firmware version
Release date of firmware version 11.2022 - - -
6.2 Modbus RS485 or Modbus TCP Function codes
Function codes are used to define which read or write action is carried out through the Modbus protocol. The
measuring device supports the following function codes:
Code Name Description Application
03 Read holding
register
Client reads one or more Modbus registers from the device.
A maximum of 125 consecutive registers can be read with 1
telegram: 1 register = 2 bytes.
The measuring device does not make a distinction between function
codes 03 and 04; these codes therefore yield the same result.
Read device parameters
with read and write
access
04 Read input
register
Client reads one or more Modbus registers from the device.
A maximum of 125 consecutive registers can be read with 1
telegram: 1 register = 2 bytes
The measuring device does not make a distinction between function
codes 03 and 04; these codes therefore yield the same result.
Read device parameters
with read Access
06
Write single
registers
Client writes a new value to one Modbus register of the measuring
device. Use function code 16 to write multiple registers with just 1
telegram.
Write only 1 device
parameter
08 Diagnostics Client checks the communication connection to the measuring device.
The following Diagnostics codes are supported:
• Sub-function 00 = Return query data (loopback test)
• Sub-function 02 = Return diagnostics register
16 Write multiple
registers
Client writes a new value to multiple Modbus registers of the device.
A maximum of 120 consecutive registers can be written with 1
telegram.
If the required device parameters are not available as a group, yet
must nevertheless be addressed with a single telegram, use Modbus
data map →  .
Write multiple device
parameters
23 Read/Write
multiple
registers
Client reads and writes a maximum of 118 Modbus registers of the
measuring device simultaneously with 1 telegram.
Write access is executed before read access.
Write and read multiple
device parameters
Broadcast messages are only allowed with function codes 06, 16, and 23.
6.3 Response time
Response time of the measuring device to the request telegram of the Modbus client is typically 3 to 5 ms.