Mitsubishi Electric 800 Series Instruction Manual page 551

(N) Operation via communication and its settings
NOTE
• When a communication option is used, the protective function [E.OP1 (fault data: HA1)] is activated at error occurrences on
the communication line. The protective function [E.1 (fault data: HF1)] is activated at error occurrences in the communication
circuit inside the option.
• Fault output indicates the Fault (ALM) signal 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 enabled, a fault record is overwritten to 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 through 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 setting)", a communication error in RS-485 terminals occurs and Pr.502 becomes
invalid.
• If the communication error setting is disabled with Pr.335 = "9999" or Pr.539 = "9999" while Pr.502 = "3 or 4", the inverter
does not operate with the frequency set in Pr.779 when a communication error occurs.
• 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 RL signal is input through an external terminal, the
operation is continued at the frequency set in Pr.779.
• During position control, an error occurs even if "2" is set in Pr.502.
CAUTION
 When Pr.502 = "3" and a communication line error occurs, or 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 through an external terminal (RES, MRS, or X92) or press the PU stop on the operation panel.
550
PARAMETERS