ProSoft Technology MVI71-MCM - Manual (Page 82)

MVI71-MCM ♦ PLC Platform Reference
Modbus Communication Module
Page 82 of 111 ProSoft Technology, Inc.
December 28, 2007
RS-232: Modem Connection
This type of connection is required between the module and a modem or other
communication device.
The "Use CTS Line" parameter for the port configuration should be set to 'Y' for
most modem applications.
RS-232: Null Modem Connection (Hardware Handshaking)
This type of connection is used when the device connected to the module
requires hardware handshaking (control and monitoring of modem signal lines).