Omron CJ1W-SCU32 Operation Manual page 153

With full-duplex mode, the reception buffer is cleared immediately before the sequence is executed.
While Recv and Send commands are executed, data is input into the reception buffer and is used as
the protocol macro data.
Transmission Time reception
mode buffer cleared
Half-duplex Immediately before
communications
sequence execution
and immediately
after Send comple-
tion by the Send or
Send&Recv com-
mand
Full-duplex Immediately before
(*1) communications
sequence execution
(*2)
*1 With full-duplex, you can use RS-232C or RS-422A/485 (1:1 and 4-wire connections) can be used. You cannot
use RS-422A/485 1:N or 2-wire connections.
*2 The Flush command can be used at any time to clear the reception buffer.
*3 Although the received data is discarded until completion of Send execution, it is reflected in the character trace.
CJ-series Serial Communications Units Operation Manual for NJ-series CPU Unit(W494)
Data reception Character
trace
From Send All during trace
completion to execution
Recv comple-
tion, Send com-
pletion to
immediately
before Send
execution
All during com- All during trace
munications execution
sequence exe-
cution
4 Using Protocol Macros
Timing chart (example)
Communications
sequence
Recv Send
Reception buffer
cleared
Data reception
(*3)
Character trace
Communications
sequence
Recv Send
Reception buffer
cleared (*3)
Data reception
Character trace
Recv
Recv
4
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