FX Series Programmable Controlers Applied Instructions 5
5-208
• Definition of special D registers and special M coils
• D8154: Waiting time for response from the inverter
If the inverter does not give a response within the time set here, after the PLC has
transmitted a command, it is regarded as no response.
When ‘0’ is set to D8154, if the inverter does not give a response in 2 seconds, it is
processed as an error.
The value is set to D8154, multiplied by 0.1(s) is treated as the judgement time for no
response.
• Use EXTR K10 (INV MON), K11 (INV CMD), K12 (RD PARAM) and K13 (WR PARAM) in
accordance with the contents of read/write communication to/from the inverter.
• For EXTR K12/K13, the PLC automatically re-writes the link parameters in accordance with
the parameter No.
For parameters relating to a second parameter of the inverter, program them using the
parameter No. adding by ‘+0’, ‘+1,000’ or ‘+2,000’.
• EXTR K10 to EXTR K13 repeatedly execute communication while the drive condition is ON.
• If two or more read instructions are driven at the same time, when the first is completed,
next is automatically executed. The step No. being executed is stored in D8155.
• Communication start
If communication is driven while the comms port is open, communication starts.
If the drive condition turns OFF during communication, communication continues until it is
completed. (The system will be adversley affected if communication is aborted by turning
OFF the drive condition.)
• Debugging function by M8154
A standby time of 15 ms is assured after communication with the inverter is completed until
next communication starts. While M8154 is ON, the standby time becomes 1,000 ms. By
monitoring D8156, the user can confirm the step which is executing communication.
M8154
Offers debugging function.
D8154
Waiting time for a response from the
inverter.
M8155
ON during communication, and OFF
when communication is complete.
D8155
Step No. of the instruction which is
executing a function related to the
inverter.
Stores ‘-1’ while communication is
not executed
M8156
Turns ON when a communication
error occurs.
Effective only just after the EXTR
instruction is executed. When the
next EXTR instruction is executed,
M8156 is cleared.
D8156
Communication command error
code
.
Updated when an error occurs in the
EXTR instruction at the next time.
Initialized to ‘-1’ by STOP
ð RUN.
M8157
Turns ON when a communication
error occurs (latch).
Reset by STOP
ð RUN
D8157
Step No. in which a communication
command error has occurred’
(Latches the step No. which
occurred for the first time after start
of run.)
Initialized to ‘-1’ by STOP
ð RUN