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14.4 Communication
If any malfunctions occur, refer to the following items after checking the power supply to the master
and the slave.
Problem
Presumed cause and solution
Communication failure
• Make sure that communication connector is securely connected.
• Check that wiring of the communication connector is correct.
(Refer to Section “12.2 Wiring”.)
• Burnout or imperfect contact on the communication cable and the
connector.
• Communication speed of the slave does not coincide with that of the
master.
(Refer to Section “12.3 Communication parameter setting”.)
• The data bit, parity and stop bit of the master do not accord with those of
the slave.
(Refer to Section “12.3 Communication parameter setting”.)
• The instrument number (address) of the slave does not coincide with that
of the command.
(Refer to Section “12.3 Communication parameter setting”.)
• The instrument numbers (addresses) are duplicated in multiple slaves.
(Refer to Section “12.3 Communication parameter setting”.)
• Make sure that the program is appropriate for the transmission timing.
(Refer to Section “12.4 Communication procedures”.)
Although communication is
occurring, the response is
“NAK”.
• Check that a non-existent command code has not been sent.
• The setting command data exceeds the setting range of the slave.
• The controller cannot be set when functions such as AT are performing.
• The KT4H/B is in the front key operation setting mode.
For all other malfunctions, please contact our main office or dealers.
