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PRC
(2) Output signals from the output module are transmitted at the rate of 30 ms per character.
For this reason, the time required to the completion of the transmission of the designated number of characters will be 30
ms
n (ms).
At 10ms interrupt intervals, the PRC instruction executes data output, strobe signal ON, and strobe signal OFF. The
other instructions are executed continuously during a period between the above processings.
Data output
OFF
Strobe signal
(3) In addition to the ASCII code, the output module also outputs a strobe signal (10 ms ON, 20 ms OFF) from the
device.
(4) Following the execution of the PRC instruction, the PRC instruction execution flag (
completion of the transmission of the designated number of characters.
(5) The PRC instruction can be used multiple times, but it is preferable to establish an interlock with the PRC instruction
execution flag (
+ 9 device) so that they will not be ON simultaneously.
D
(6) If no comments have been registered at the device designated by
(7) When a comment is read, SM720 turns ON for one scan after the instruction is completed.
SM721 turns ON during the execution of the instruction.
The PRC instruction cannot be executed while SM721 is ON. If the attempt is made, no processing is performed.
1. For device comments used with the PRC instruction, use comment files stored in the standard ROM or memory card.
Comment files stored in the program memory cannot be used.
2. The comment file used by the PRC instruction is set at the "PLC File Setting" option in the PLC parameter dialog box.
If no comment file has been set for use by the PLC file setting, it will not be possible to output device comments with the
PRC instruction.
3. Do not execute the PRC instruction during an interrupt program.
Otherwise, malfunction may occur.
Operation Error
(1) In the following case, an operation error occurs, the error flag (SM0) turns ON, and an error code is stored into SD0.
Error
code
The PRC instruction is executed while a comment is written during
4100
RUN.
436
Execution of sequence program
ON
10 ms
10 ms
10 ms
10 ms
30 ms
Error details
Processing of PRC instruction
10 ms
+ 9 device) remains ON until the
D
, processing will not be performed.
S
Q00J/
Q00/
QnH
QnPH QnPRH
Q01
––
+ 8
D
QnU
LCPU
––
––
––
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