Mitsubishi Electric 800 Series Instruction Manual page 483

NOTE
• Fault output indicates the Fault signal (ALM) and an alarm bit output.
• When the fault output is set enabled, fault records are stored in the fault history. (A fault record is written to the fault history
at a fault output.)
• When the fault output is not set enabled, fault record is overwritten to the fault history of the fault history temporarily but
not stored.
• After the fault is removed, the fault indication goes back to normal indication on the monitor, and the fault history goes back
to the previous status.
• When Pr.502 ≠ "0", the normal deceleration time setting (settings like Pr.8, Pr.44, and Pr.45) is applied as the deceleration
time. Normal acceleration time setting (settings like Pr.7 and Pr.44) is applied as the acceleration time for restart.
• When Pr.502 = "2, 3, or 4", the inverter operates with the start command and the speed command, which were used before
the fault.
• If a communication line error occurs, then the error is removed during deceleration while Pr.502 = "2", the motor re-
accelerates from that point. (When a communication option is used, acceleration does not restart at a communication
option error.)
• The Pr.502 and Pr.779 settings are valid when communication is performed via the RS-485 terminals or a communication
option.
• These parameters are valid under the Network operation mode. When performing communication with RS-485 terminals,
set Pr.551 PU mode operation command source selection ≠ "1".
• Pr.502 is valid for the device that has the command source under the Network operation mode. If a communication option
is installed while Pr.550 = "9999 (initial value)", a communication error in RS-485 terminals occurs and Pr.502 becomes
invalid.
• If the communication error setting is disabled with Pr.502 = "3 or 4", Pr.335 = "9999", and Pr.539 = "9999", the inverter
does not continue its operation with the frequency set by Pr.779 at a communication error.
• If a communication error occurs while continuous operation at Pr.779 is selected with Pr.502 = "3 or 4", the inverter
operates at the frequency set in Pr.779 even though the speed command source is at the external terminals.
• Example) If a communication error occurs while Pr.339 = "2" and the external terminal RL is ON, the operation is continued
at the frequency set in Pr.779.
CAUTION
• When Pr.502 = "3" and a communication line error occurs, or a Pr.502 = "4" and a communication line error or a communication option
fault occurs, the operation continues. When setting "3 or 4" in Pr.502, provide a safety stop countermeasure other than via
communication. For example, input a signal (RES or MRS) through an external terminal or press the PU stop on the operation panel.
Parameters referred to
Pr.7 Acceleration time, Pr.8 Deceleration time
Pr.335 RS-485 communication retry count
Pr.336 RS-485 communication check time interval
Pr.539 MODBUS RTU communication check time interval
Pr.550 NET mode operation command source selection
Pr.551 PU mode operation command source selection
482
5. PARAMETERS
5.12 (N) Operation via communication and its settings
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