Register Information; Response Time; Modbus Data Map - Endress+Hauser SpectraSensors J22 TDLAS Operating Instructions Manual

J22 TDLAS Gas Analyzer
Code
08 Diagnostics
16 Write multiple
registers
23 Read/Write
multiple
registers
SpectraSensors, Inc.
Name
Master checks the communication
connection to the measuring device.
The following "Diagnostics codes" are
supported:
•
•
Master writes a new value to
multiple Modbus registers of the
device.
A maximum of 120 consecutive
registers can be written with 1
telegram.
Master reads and writes a
maximum of 118 Modbus registers of
the measuring device
simultaneously with 1 telegram.
Write access is executed before
read access.
Broadcast messages are only allowed with function codes 06, 16 and 23.

Register information

For an overview of device parameters with their respective Modbus register
information, please refer to the "Modbus RS485 register information" section in
the "Device Parameters Description" documentation →  2.

Response time

Response time of the measuring device to the request telegram of the Modbus
client: typically 3 to 5 ms.

Modbus data map

Function of the Modbus data map
The device offers a special memory area, the Modbus data map (for a maximum
of 16 device parameters), to allow users to call up multiple device parameters via
Modbus RS485 and not only individual device parameters or a group of
consecutive device parameters.
Grouping of device parameters is flexible and the Modbus client can read or write
to the entire data block simultaneously with a single request telegram.
Description
Sub-function 00 = Return
query data (loopback test)
Sub-function 02 = Return
diagnostics register
If the required device param-
eters are not available as a
group, yet must nevertheless
be addressed with a single
telegram, use Modbus data
map →  49
4900002277
Application
Write multiple device param-
eters
Write and read multiple
device parameters
49