Operation Selection At Communication Error Occurrence (Pr. 121, Pr. 122, Pr. 502, Pr. 779) - Mitsubishi Electric FR-D720-0.2K-G Instruction Manual

4.17.3 Operation selection at communication error occurrence
(Pr. 121, Pr. 122, Pr. 502, Pr. 779)
You can select the drive unit operation when a communication line error occurs during RS-485 communication from the
PU connector. The operation is active under the Network operation mode.
Parameter
Name
Number
Number of PU
121 communication
retries
PU communication
122
check time interval
Stop mode
selection at
502
communication
error
Operation speed
during
779
communication
error
The above parameters can be set when Pr. 160 Extended function display selection = "0".

The value left of the slash is for the 2.2K drive unit or lower. The one right of the slash is for the 3.7K drive unit.

If a value exceeding the upper speed limit of the motor is set, the actual operation will be limited at the maximum rotation speed. The setting range is for
the S-PM motor. The maximum setting value differs depending on the number of poles of the applied motor.
Communication operation and setting
Initial
Setting Range
Value
Number of retries at data receive error occurrence. If the number of
consecutive errors exceeds the permissible value, the drive unit will
0 to 10
come to trip (depends on Pr. 502).
1
Valid only Mitsubishi drive unit (computer link operation) protocol
If a communication error occurs, the drive unit will not come to trip.
9999
(NET operation mode at initial value)
RS-485 communication can be made. Note that a communication
fault (E.PUE) occurs as soon as the drive unit is switched to the
0s
operation mode with command source. (NET operation mode at
initial value)
Communication check (signal loss detection) time interval
0s
0.1 to 999.8s If a no-communication state persists for longer than the permissible
time, the drive unit will come to trip (depends on Pr. 502).
9999 No communication check (signal loss detection)
occurrence
0 Coasts to stop
Decelerates to
0 1
stop
Decelerates to
2
stop
Continues
3
running at Pr. 779
0 to 12000r/min /
0 to 8000r/min Motor runs at the specified speed at a communication error.
9999 
9999 Motor runs at the speed used before the communication error.
Description
At fault
Indication
E.PUE Output
After stop Output
E.PUE after stop
After stop Without
E.PUE output
Without
—
output
(Refer to page 161.)
Fault
At fault removal
output
Stop
(E.PUE)
Stop
(E.PUE)
Automatic restart
functions
Operates in normal
condition
185
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