Omron SYSMAC CS1W-SCB41-V1 Operation Manual page 185

Setup Area Allocations
Transmission Time reception
mode buffer cleared
Half-duplex Immediately before
communications
sequence execution
and immediately
following SEND
completion by the
SEND or
SEND&RECV
command
Full-duplex Immediately before
(See note 1) communications
sequence execution
(See note 2)
Note
156
Also, if the external device is connected using 2-wire connections from an RS-
422A/485 port, send and receive data cannot both be on the same transmis-
sion line at the same time. This will create an additional lag time, t2, or 150 µ s.
If responses are being received quickly from the external device, i.e., faster
than t1 +t2, create a send delay at the external device or take other measures
to allow for the lag times.
SEND
operation
Data send
processing
Rapid
response
Data
reception
Time Lag t1
Baud rate (bps)
1,200 1,116
2,400 578
4,800 288
9,600 144
19,200 73
38,400 36
57,600 24
With full-duplex mode, the reception buffer is cleared immediately before the
sequence is executed. While both the SEND&RECV commands are being
executed, data is input into the reception buffer and is used as the macro
data.
Data reception Character trace
From SEND All during trace
completion to execution
RECV
completion, or
following SEND
completion to
immediately
before SEND
execution
All during All during trace
communications execution
sequence
execution
1. With full-duplex, RS-232C or RS-422A/485 (1:1 and 4-wire connections)
can be used. RS-422A/485 1:N or 2-wire transmissions cannot be used.
2. The FLUSH command is used to clear the reception buffer, and can be
used at any time.
3. Although the received data is discarded until completion of SEND execu-
tion, it is reflected in the character trace.
t1 t2 = 150 µs
Time lags (see following table)
Reception buffer cleared
Time lag (µs)
Timing chart (example)
Communications
sequence
Reception buffer
cleared
Data reception
Character trace
Communications
sequence
Reception buffer
cleared
Data reception
Character trace
Section 5-2
Data cannot be received
during this time.
RECV SEND RECV
(See note 3.)
RECV SEND RECV