GE PACSystems RX7i - Chapter 6 Serial I;O, SNP & RTU Protocols

GFK-2222AD April 2018 201
Chapter 6 Serial I/O, SNP & RTU Protocols
This chapter discusses the following topics related to communications on CPU serial ports COM1 and
COM2:
▪ Configuring Serial Ports Using COMMREQ Function 65520
▪ Serial I/O Protocol
▪ RTU Slave Protocol
▪ SNP Slave Protocol
Details of the RTU and SNP protocol are described in the Series 90 PLC Serial Communications User’s
Manual, GFK-0582.