B&B Electronics ADAM-5000_TCP - Manual - Manual (Page 100)

Planning Your Application Program
And the response should be:
Chapter 6
Figure 6-2: Response Comment Structure
6-3-2 Modbus Function Code Introduction
To full-fill the programming requirement, there is a series of function code
standard for user’s reference...
Code (Hex) Name Usage
01 Read Coil Status Read Discrete Output Bit
02 Read Input Status Read Discrete Input Bit
03 Read Holding Registers Read 16-bit register. Used to read integer or
04 Read Input Registers
floating point process data.
05 Force Single Coil Write data to force coil ON/OFF
06 Preset Single Register Write data in 16-bit integer format
08 Loopback Diagnosis Diagnostic testing of the communication port
15 Force Multiple Coils Write multiple data to force coil ON/OFF
16 Preset Multiple Registers Write multiple data in 16-bit integer format
Table 6-1: Response Comment Structure
Function Code 01
The function code 01 is used to read the discrete output’s ON/OFF sta-
tus of ADAM-5000/TCP in a binary data format. Request message
format for function code 01:
Command Body
Station
Address
Function
Code
Start
Address
High Byte
Start
Address
Low Byte
Requested
Number of Coil
High Byte
Requested
Number of
Coil Low Byte
ADAM-5000/TCP User’s Manual 6-33