Device Monitoring - ProMinent DULCO flex Control Original Operating Instructions

Supplementary operating instructions for Modbus RTU
2.5.1.2 Function codes
Tab. 26: 16 bit values
Function code
0x03 (3)
0x06 (6)
0x10 (16)
0x17 (23)
2.5.1.3 Data
2.5.1.4 CRC check sum

2.6 Device monitoring

30
Command
'Read Holding Register'
'Write Single Register'
'Write Multiple Register'
'Read / Write Multiple Register'
Not all registers support all commands.
can only be called up with function code 3.
Maximum message size
Excessive message sizes may disrupt the commu‐
nication.
The maximum message size for the 'Read Holding
Register' function is 200 bytes at 19,200 baud
(100 bytes at 9600 baud or 400 bytes at 38,400
baud).
The length and content of a data field depends on whether we are
dealing with a request or a response telegram:
Tab. 27: Request telegram
Length
2 bytes
2 bytes
Tab. 28: Response telegram
Length
1 bytes
n bytes
The check sum can be calculated with the following tool:
https://www.lammertbies.nl/comm/info/crc-calculation.html .
The monitoring time for device monitoring can be changed in the
menu.
Maximum register number in one
transaction
125
1
123
Read: 125 / Write: 121
'Read Holding Register'
Content
Register
Number of registers to be trans‐
ferred
Content
Number of bytes to be transferred
Content of registers requested