ProSoft Technology inRax MVI69-101M User Manual page 101

Reference
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).
RS-232: Null Modem Connection (No Hardware Handshaking)
This type of connection can be used to connect the module to a computer or field
device communication port.
Note: If the port is configured with the "Use CTS Line" set to 'Y', then a jumper is required between
the RTS and the CTS line on the module connection.
ProSoft Technology, Inc.
February 4, 2008
MVI69-101M ♦ CompactLogix or MicroLogix Platform
IEC 60870-5-101 Master Communication Module
Page 101 of 133