FPΣ User's Manual 
 
8.8 Modbus RTU Communication 
247 
8.8.1  Setting Communication Parameters 
Make the following settings for the communication port: 
• communication mode (MEWTOCOL-COM) 
• station number 
• baud rate 
• communication format 
For details on setting the communication parameters, see "
Setting System Registers in PROG 
Mode" on page 
165. 
 
NOTE
 
•  The end code setting must always be "CR", and the start code setting must 
be "No STX". 
•  The station number can be set within a range of 1 to 99. 
•  With a C-NET adapter, a maximum of 32 stations can be specified. 
 
8.8.2  Sample Program for Master Communication 
Use the F145_WRITE and F146_READ instructions for the Modbus master function. Be sure 
to select "Modbus RTU Master/Slave" for the COM port in system register 412. 
POU Header
 
 
In order to have consistent data in the master project and in the slave project, the common 
data should be kept in the GVL of a common library.