Zener MSC-3 - Modbus Function Code Details; Function Code 01: Read Coils; Function Code 02: Read Discrete Inputs; Function Code 03: Read Holding Registers

IM00120
126
IM00120
MSC-3 Start Up
Function Code 01: Read Coils
Request:
Function code 1 byte 1
Starting address 2 bytes 0 to 4
Quantity of coils 2 bytes 1 to 5
Response:
Function code 1 byte 1
Byte count 1 byte 1
Coil status 1 byte MSC-3 coils states
Error:
Function code 1 byte 129 (128+function code, 0x81)
Exception code 1 byte 1, 2 or 3
Function Code 02: Read Discrete Inputs
Request:
Function code 1 byte 2
Starting address 2 bytes 0 to 20
Quantity of coils 2 bytes 1 to 21
Response:
Function code 1 byte 2
Byte count 1 byte 1 to 3
Coil status 1 to 3 bytes MSC-3 discrete input states
Error:
Function code 1 byte 130 (128+function code, 0x82)
Exception code 1 byte 1, 2 or 3
Function Code 03: Read Holding Registers
Request:
Function code 1 byte 3
Starting address 2 bytes 0 to 9
Quantity of registers 2 bytes 1 to 10
Response:
Function code 1 byte 3
Byte count 1 byte 2 x (Quantity of registers)
Register value(s) 2 x (Quantity of registers) bytes MSC-3 holding register(s)
Error:
Function code 1 byte 131 (128+function code, 0x83)
Exception code 1 byte 1, 2 or 3