SE2000 SERIES CONTROLLERS (VERSION4.0)
RS-485 COMMUNICATION INSTRUCTION MANUAL
MODBUS Protocol Reference Guide
1. COMMUNICATION FUNCTIONS
1.1 General -----------------------------------------------------------------------------------------1
2. SPECIFICATIONS
2.1 Communication Specifications --------------------------------------------------------1
3. CONNECTION
3.1 Terminal Allocation ------------------------------------------------------------------------1
3.2 Wiring ------------------------------------------------------------------------------------------2
4. SETTING OF COMMUNICATION CONDITION
4.1 Set Items --------------------------------------------------------------------------------------2
4.2 Setting Operation Method ---------------------------------------------------------------2
5. MODBUS COMMUNICATION PROTOCOL
5.1 General -----------------------------------------------------------------------------------------3
5.2 Composition of Message ---------------------------------------------------------------3
5.3 Response of Slave Station --------------------------------------------------------------4
5.4 Function Code -------------------------------------------------------------------------------4
5.5 Calculation of Error Check Code (CRC-16) ----------------------------------------4
5.6 Transmission Control Procedure -----------------------------------------------------5
6. DETAILS OF MESSAGE
6.1 Read-out of Word Data [Function Code: 03] ---------------------------------------6
6.2 Read-out of Read-Only Word Data [Function Code: 04] ------------------------6
6.3 Write-in of Word Data (1 word) [Function Code: 06] ----------------------------7
7. ADDRESS MAP AND DATA FORMAT
7.1 Data Format ----------------------------------------------------------------------------------7
7.2 Data Address Map --------------------------------------------------------------------------8
8. TROUBLESHOOTING
8.1 Troubleshooting ----------------------------------------------------------------------------8
