Instruction Manual

Appendix A: Modbus Protocol PPC-2000 User’s Guide
276 Watlow Anafaze Doc.# 30002-00 Rev 2.3
Function Codes
The listing below shows the function codes supported by the
PPC controllers. Codes are listed in decimal.
Table A.2 Function Codes
Read Coil Status 01
Reads the On/Off status of discrete outputs (0X references,
coils) in the slave. Broadcast is not supported.
Read Input Status 02
Reads the On/Off status of discrete inputs (1X references) in
the slave. Broadcast is not supported.
Read Holding Registers 03
Reads the binary contents of holding registers (4X references)
in the slave. Broadcast is not supported.
Read Input Registers 04
Reads the binary contents of input registers (3X references) in
the slave. Broadcast is not supported.
Force Single Coil 05
Forces a single coil (0X reference) to either On or OFF. When
broadcast, the function forces the same coil reference in all
attached slaves.
Preset Single Register 06
Presets a value into a single holding register (4X reference).
When broadcast, the function presets the same register
reference in all attached slaves.
Code
Decimal
Name
01 Read Coil Status
02 Read Input Status
03 Read Holding Registers
04 Read Input Registers
05 Force Single Coil
06 Preset Single Register
08 Diagnostics
15 Force Multiple Coils
16 Preset Multiple Registers