FX Series Programmable Controlers Applied Instructions 5
5-209
5.16.1.1.10 Consistency with other instructions
• STL instruction
During communication, if the executed state is set to OFF, the communication port is not
open. As a result, communication is disabled.
• Branch instructions CJ and CJP
During communication, if the EXTR instruction is skipped by a CJ or CJP instruction, the
communication port is not open. As a result, communication is disabled.
• Description in subroutine
As the EXTR instruction requires the time of two or more operation cycles until execution is
complete, it is prohibited to write a subroutine where the EXTR instruction is called twice or
more in one operation cycle.
• Inside master control
No problems are expected.
• FOR-NEXT
It is prohibited to use an EXTR instruction together with a FOR-NEXT instruction.
• Description in interrupt
It is prohibited to describe an EXTR instruction in any interrupt.
• Cautions on write during run
(1) It is prohibited to rewrite the function No. of theEXTR instructions first parameter.
(If the function No. is rewritten during run, a problem will occur in the same way as change
in the application instruction No.)
(2) It is prohibited to delete an EXTR instruction.
(If the EXTR instruction is deleted during run, communication will be disabled.)
• Communication complete
When communication is finished, the completion flag M8029 turns ON, without regard to the
completion status (normal or abnormal).
(M8029 turns ON for one calculation cycle at the time of completion.
M8029 is used by manu instructions and therefore the ON/OFF status of M8029 is held only
until the next instruction which utilizes M8029 is executed.)
• Communication error
Communication is executed three times in total, including two retries. If communication is
abnormally finished even after the third execution, it is regarded as an error. Error types are
classified as follows.
1) When an error code is returned from the inverter
2) When the inverter does not give any response
3) When a response is given by an unspecified station
4) When a receive error (such as overrun, parity error and framing error) occurs
5) When M8063 turns ON and error code 6301 is set to D8067
6) When the check sum of the data returned by the inverter does not match
For 1), 2) & 3) M8156 is set to ON, and an error code is set to D8156.
If a communication error occurs, it is cleared when the next EXTR K10/K11/K12/K13 is
executed.
In general when an error occurs, M8157 turns ON and remains ON (latch) until it is set OFF.
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