SetPro
MV Series Controllers RS-485 Communication Instruction Manual
MODBUS Protocol Reference Guide
1. COMMUNICATION FUNCTIONS
1.1 General -----------------------------------------------------------------------------1
2. SPECIFICATIONS
2.1 Communication Specifications ----------------------------------------------------2
3. CONNECTION
3.1 Terminal Allocation ----------------------------------------------------------------3
3.2 Wiring ------------------------------------------------------------------------------3
4. SETTING OF COMMUNICATION CONDITION
4.1 Set Items ---------------------------------------------------------------------------4
4.2 Setting Operation Method --------------------------------------------------------5
5. MODBUS COMMUNICATION PROTOCOL
5.1 General -----------------------------------------------------------------------------6
5.2 Composition of Message ----------------------------------------------------------6
5.3 Response of Slave Station ---------------------------------------------------------7
5.4 Function Code ---------------------------------------------------------------------8
5.5 Calculation of Error Check Code (CRC-16) ----------------------------------------8
5.6 Transmission Control Procedure --------------------------------------------------9
6. DETAILS OF MESSAGE
6.1 Read-out of Word Data [Function Code: 03] -------------------------------------11
6.2 Read-out of Read-Only Word Data [Function Code: 04] -------------------------12
6.3 Write-in of Word Data (1 word) [Function Code: 06] -----------------------------13
7. ADDRESS MAP AND DATA FORMAT
7.1 Data Format -----------------------------------------------------------------------14
7.2 Data Address Map ----------------------------------------------------------------15
8. TROUBLESHOOTING
8.1 Troubleshooting ------------------------------------------------------------------17
