Df1 half-duplex slave -6 df1 half duplex master -6, Df1 half-duplex slave, Df1 half duplex master – Rockwell Automation DAG6.5.8 APPLICATION GUIDE SCADA SYSTEM User Manual
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Publication AG-UM008C-EN-P - February 2005
4-6 Configuring SLC 5/03, 5/04, and 5/05 Processors
DF1 Half-Duplex Slave
When configured for DF1 half-duplex slave, the following control line
operation takes effect:
No Handshaking Selected
DTR is always active and RTS is always inactive. Receptions and
transmissions take place regardless of the states of DSR, CTS, or DCD
inputs. Only make this selection when the processor is directly
connected to another device that does not require handshaking
signals.
Half-Duplex Modem with Continuous Carrier Selected
DTR is always active and RTS is only activated during transmissions
(and any programmed delays before or after transmissions). The
handling of DCD and DSR are exactly the same as with Full-Duplex
Modem. Reception requires DSR and DCD to be active. Transmissions
require CTS, DCD and DSR to be active. Whenever DSR and DCD are
both active, the modem lost bit is reset.
Half-Duplex Modem without Continuous Carrier Selected
This is exactly the same as Half-Duplex Modem with Continuous
Carrier except monitoring of DCD is not performed. DCD is still
required for receptions, but is not required for transmissions.
Transmissions still require CTS and DSR. Whenever DSR is active, the
modem lost bit is reset.
DF1 Half Duplex Master
When configuring for DF1 half-duplex master, the following control
line operation takes effect:
No Handshaking Selected
DTR is always active and RTS is always inactive. Receptions and
transmissions take place regardless of the states of DSR, CTS, or DCD
inputs. Only make this selection when the processor is directly
connected to another device that does not require handshaking
signals.