Rockwell Automation DAG6.5.8 APPLICATION GUIDE SCADA SYSTEM - Manual (Page 78)

Publication AG-UM008C-EN-P - February 2005
3-10 Configuring MicroLogix 1100/1200/1500 Controllers
Half-Duplex Modem with DCD Handshaking (MicroLogix 1500 LRP Channel 1
Only) Selected
RTS is activated during transmissions and during any programmed
delays before and after transmissions. Programmed delays include RTS
Send Delay and RTS Off Delay. The DCD input signal is monitored to
determine if transmissions are acceptable. If DCD is active, receptions
are possible.
Transmissions require CTS to be active and DCD to be inactive. If
DCD is active at the onset of transmission, a configured delay (DCD
Wait Delay) will wait for DCD to become inactive before discarding
the packet. If CTS is inactive at the onset of transmission, one second
will be provided to wait for CTS to become active before the message
packet is discarded.