Rainbow Robotics RB Series, User Manual

Page: 426 / 440

RAINBOW ROBOTICS
RB SERIES _ USER MANUAL
© RAINBOW ROBOTICS Inc. All rights reserved.
426
APPENDIX I. MODBUS TCP SERVER

Warning
This manual describes the Modbus server (slave controller). See Section 6 for a
description of the Modbus client features.
1. Overview
RB's Modbus TCP server (slave controller) is fixed at port number 502. The IP address
changes depending on the network settings through the UI. (The initial IP address is
10.0.2.7.)
RB's Modbus server allows the connection of multiple clients and executes the following
operation commands.
Function Code Function Name
Bit
Address
2 Read Discrete Inputs
1 Read Coils
5 Write Single Coil
15 Write Multiple Coils
16-bit
(Word)
Address
4 Read Input Registers
3 Read Multiple Holding Registers
6 Write Single Holding Register
16 Write Multiple Holding Registers
2. Exception Code
The following error message is returned when accessing the wrong address, incorrect range
of values, or invalid command sent.
Exception Code Exception Name
1 Illegal Function
2 Illegal Data Address
3 Illegal Value