HTP 7350P-629 - Manual (Page 10)

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Figure 4 – Modbus Diagnostic LEDs
C. MODBUS COMMUNICATION
The Modbus communication commands can be found in Parts 3 and 4 of this manual, and exception codes supported by the
communication board can be found in Part 5, Section E.
D. MODBUS FUNCTION SET
FUNCTION SUB FUNCTION
HEX DESCRIPTION
DEC HEX DEC
1 01 Read coil status
2 02 Read input status
3 03 Read holding registers
4 04 Read input registers
5 05 Force single coil
6 06 Preset single register
7 07 Read exception status
8 08 0 00 Diagnostic – Return query data
1 01 Diagnostic – Restart communication
2 02 Diagnostic – Return diagnostic register
4 04 Diagnostic – Force listen mode
10 0A Diagnostic – Clear counters and diagnostic registers
11 0B Diagnostic – Return bus message count
12 0C Diagnostic – Return bus exception error count
13 0D Diagnostic – Bus exception error count
14 0E Diagnostic – Return follower message count
15 0F Diagnostic – Return communication error count
16 10 Diagnostic – Return follower NAK count