Owners manual

Modbus Protocol User Guide 3
Contents
Figures 4
Tables 4
1: Introduction 5
Modbus ___________________________________________________________ 5
Extended Modbus System Example _____________________________________ 6
Modbus/TCP Master Talking to Modbus/TCP Slave _____________________________ 6
Modbus/TCP Master Talking to Modbus/RTU Serial Slave ________________________ 7
Modbus/RTU Serial Master Talking to Modbus/TCP Slave ________________________ 7
Modbus/RTU Serial Master Talking to Modbus/RTU Serial Slave ___________________ 7
2: Configuring Modbus 8
Network Protocols ___________________________________________________ 8
Packing Algorithm ___________________________________________________ 8
IP Address_________________________________________________________ 8
Configuration Methods _______________________________________________ 9
IAP Device Server’s IP Address ________________________________________ 9
Using the Setup Mode Screen__________________________________________ 9
Basic Commands (D/S/Q) ____________________________________________ 10
Default Settings (D)______________________________________________________ 10
Save (S) ______________________________________________________________ 10
Quit Without Saving (Q) __________________________________________________ 10
Network/IP Settings_________________________________________________ 11
IP Address_____________________________________________________________ 11
Set Gateway IP Address (Y/N) _____________________________________________ 11
Set Netmask (N for default) _______________________________________________ 11
Telnet Configuration Password_____________________________________________ 11
Serial and Mode Settings ____________________________________________ 11
Attached Device (1=Slave, 2=Master) _______________________________________ 11
Serial Protocol (1=Modbus/RTU, 2=Modbus/ASCII) ____________________________ 12
Interface Type (1=RS232 2=RS422/RS485+4-wire 3=RS485+2-wire) ______________ 12
Enter Serial Parameters (B,D,P,S) __________________________________________ 12
Modem Control Settings _____________________________________________ 12
RTS/CTS Mode (1=Fixed 2=Variable) _______________________________________ 12
Delay after Output of RTS (0-1275 ms, 5ms increments)_________________________ 13
Wait for CTS to Go Active (N/Y) ____________________________________________ 13