Mitsubishi Electric MELSEC-Q/L Programming Manual page 518

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Table of Contents

[Timing Chart]

(Strobe signal)

(Flag indicating strobe signal

is being output)

(File access in progress flag)

(File access completion flag)

• Output signals from the output module are transmitted at the rate of 30ms per character. For this reason, the time required

to the completion of the transmission of the designated number of characters will be 30ms  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.

Strobe signal

• In addition to the ASCII code, the output module also outputs a strobe signal (10ms ON, 20ms OFF) from the (D)+8 device.

• Following the execution of the PRC instruction, the PRC instruction execution flag ((D)+9 device) remains ON until the

completion of the transmission of the designated number of characters.

• The PRC instruction can be used multiple times, but it is preferable to establish an interlock with the PRC instruction

execution flag ((D)+9 device) so that they will not be ON simultaneously.

• If no comments have been registered at the device designated by (S), processing will not be performed.

• 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.

7 APPLICATION INSTRUCTIONS

7.9 Display Instructions

Preprocessing

(several scans)

instructions can

be executed.

Execution of sequence program

30ms × 16 = 480ms

PRC instruction cannot be executed again.

Instructions other than PRC instruction (SP.FREAD, SP.FWRITE,

PUNROAD, PLOAD, PSWAPP) can be executed.

Processing of PRC instruction