Mitsubishi Electric FR-A800, Instruction Manual

Page: 789 / 1042

Parameters (N) Operation via communication and its settings
FR-A800 5 - 609
NOTES 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 faults history. (A fault record is
written to the faults history at a fault output.)
When the fault output is not set enabled, fault record is overwritten to the faults history of the
faults history temporarily but not stored.
After the fault is removed, the fault indication goes back to normal indication on the monitor, and
the faults history goes back to the previous status.
If Pr. 502 is set to "1, 2, or 3", 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 or 3", 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.
The Pr. 502 and Pr. 779 settings are valid when communication is performed via the RS-485 termi-
nals or a communication option.
These parameters are valid under the Network operation mode. When performing communica-
tion with RS-485 terminals, set Pr. 551 "PU mode operation command source selection" to "2 (ini-
tial value)".
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", Pr. 335 = "9999", and Pr. 539 =
"9999", the inverter does not continue its operation with the frequency set by Pr. 779 at a commu-
nication error.
If a communication error occurs while continuous operation at Pr. 779 is selected with Pr. 502 =
"3", 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.
During position control, a fault is output without deceleration even if Pr. 502 = "2".
Parameters referred to
Pr. 7 Acceleration time => page 5-233
Pr. 8 Deceleration time => page 5-233
Pr. 335 RS-485 communication retry count => page 5-610
Pr. 336 RS-485 communication check time interval => page 5-610
Pr. 539 MODBUS RTU communication check time interval => page 5-630
Pr. 550 NET mode operation command source selection => page 5-274
Pr. 551 PU mode operation command source selection => page 5-274