Bender COMTRAXX COM465IP - Modbus Response Structure; Exception Code Structure; Modbus Address Structure for BMS Devices

Modbus TCP server
40
COM465IP-COM465DP_D00216_02_M_XXEN/03.2017
6.1.3 Modbus responses
The responses consist of 2 bytes per register. The MSB is the first byte.
6.1.4 Structure of the exception code
6.1.5 Modbus address structure for BMS devices
Byte Name Example
…… …
Byte 7 MODBUS function code 0x04
Byte 8 Byte count 0x04
Byte 9, 10 Value register 0 0x1234 (fictitious value)
Byte 11, 12 Value register 1 0x2345 (fictitious value)
Byte Name Example
…… …
Byte 7 MODBUS function code 0x84
Byte 8 Exception code 0x01 or 0x02
Function Address range
Number of
bytes
Number of
words
Device type 0x00…0x09 20 bytes 10 words
Timestamp 0x0A…0x0D 8 bytes 4 words
Common alarm
0x0E
(high byte)
1 byte 0.5 words
No BMS bus
connection
0x0E
(low byte)
1 byte 0.5 words
Not used 0x0F 2 bytes 1 word
Channel 1…32 0x10…0x8F 32 x 8 bytes 128 words
Alarm and test
Channel 33…64
0x90…0xFC 218 x 8 bytes 109 words