Product Description

The Serial Interface consists of a serial card and a terminal

block. The card contains two serial communications

ports that support RS232 and RS422/485 half duplex, or

RS422/485 full duplex signals. These ports are individually

configurable and support data rates from 300 Baud up to

115 KBaud.

The S-series card plugs into an 8-wide I/O carriers in any of

the possible 64 slots and communicates with the S-series

controllers. LEDs, located on the front of the card, show the

power, error, and port status of the interface at a glance.

The standard Modbus protocol includes the Serial Interface,

the Modbus RTU, and ASCII communications protocol

as defined in the Modicon Modbus Protocol Reference

Manual dated March 1992 (PI-MBUS-300 REV D). Each Serial

Interface port may be configured as either a master or

slave device.

The serial card supports the following features using the

Modbus protocol:

• Reading input data from Modbus coils, input status,

holding registers and normal input registers.

• Writing output data to coils and holding registers.

• Output data can be written in single coil, register mode,

or complete data set mode. This output mode is a

configurable parameter.

• Input data can be read in as a complete data set,

providing the best performance.