426
The following program shows how to synchronize data transmission during
asynchronous operation using IOSP(187) and IORS(188).
In the program in PC A (the sending PC), the data is set in memory while the
Enabled Flag is ON, i.e., when SEND(192) is not being executed, and a code is
added in the last word of data to verify that the data has been transmitted suc-
cessfully.
In the program in PC B (the receiving PC), the code in the last word of the trans-
mitted data is used to prevent more data from being transferred until the trans-
mitted data is copied to another section of Data Memory for storage. The code is
erased from the original block of data after it is copied.
S
L
K
C
P
U
P
S
S
L
K
C
P
U
P
S
PC A PC B
jSEND D00000 D01000 D02000
SEND
(004)
JMP 000
(020)
CMP #AAAA D01255
$AAAA
(040)
XFER #0255 D01000 D02000
(187)
IOSP
A500
13
A500
06
(188)
IORS
(005)
JME 00
(030)
M0V #0000 D01255
Data
Terminator set in send data
at PC A.
Programming Example:
Synchronizing Data
Network Instructions Section 5-36
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