Panasonic AFP7CPS4E, Руководство пользователя

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9.5 Sending/Receiving Flag Operation
9-15
9.5 Sending/Receiving Flag Operation
9.5.1 No Header (Start Code), Terminator (End Code) "CR":
The “reception done” flag, the “sending active” flag, the GPSEND instruction, and the
GPRECV instruction are related as follows:
A
B
C
CR
D F
G
1 3 CR
B
C
A
3
ON
OFF
ON
OFF
ON
OFF
ON
OFF
E
2
A D A
B B
C
A
<1> <2> <3>
E
D
E
F
D
E
F
G
D
<2> <3> <4> <1>
Data received
from external
device
SCU
receive bu ffer
No. of bytes
received
Transmitted
data
Receive bu ffer
specified using
GPRECV instruction
Reception
done flag
X0, X1, X2, X3
General-purpose
communication
Sending active flag
Y8, Y9, YA, YB
GPRECV
instruction
execution
GPSEND
instruction
execution
Stored
W
rit
e poin
ter
Data can be received until eight
receive bu ffers are all filled up even
if the reception done flag is turned on.
After GPRECV instruction is
executed, reception done
flag turns off at the beginning
of next scan or later.
No. of bytes received

The COM port has eight reception buffers. The reception process is continued after the
reception done flag (X0, X1, X2, X3) turns ON. The reception done flag (X0, X1, X2) does
not turn OFF immediately following the execution of GPRECV instruction. It will be turned off
at the beginning of the next scan or later.

After GPSEND instruction is executed, data transmission is started in several
μ
s to several
tens of ms. For time before transmission is started, please refer to the communication cycle
time (SM208-SM210) using the system monitor function.
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