Rockwell Automation DAG6.5.8 APPLICATION GUIDE SCADA SYSTEM - Manual (Page 76)

Publication AG-UM008C-EN-P - February 2005
3-8 Configuring MicroLogix 1100/1200/1500 Controllers
Modem Control Line
Operation The following explains the operation of the MicroLogix
1100/1200/1500 controllers when you configure the RS-232 channel
for the following applications.
DF1 Full-Duplex
When configured for DF1 full-duplex, the following control line
operation takes effect:
No Handshaking Selected
RTS is always inactive (low). Receptions and transmissions take place
regardless of the state of CTS input. Only make this selection when
the MicroLogix 1100/1200/1500 controllers are directly connected to
another device that does not require handshaking signals.
Full-Duplex Modem (RTS On) Selected
RTS is always active (high).
Transmissions require CTS to be active.
DF1 Half-Duplex Slave
When configured for DF1 half-duplex slave, the following control line
operation takes effect:
No Handshaking Selected
RTS is always inactive. Receptions and transmissions take place
regardless of the state of CTS input. Only make this selection when
the controller is directly connected to another device that does not
require handshaking signals.
Half-Duplex Modem (RTS/CTS Handshaking) Selected
RTS is only activated during transmissions (and any programmed
delays before or after transmissions). Transmissions require CTS to be
active.