168
Communication operation and setting
4.16.3 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
Number
Name
Initial
Value
Setting Range Description
121
Number of PU
communication
retries
1
0 to 10
Number of retries at data receive error occurrence. If the number of
consecutive errors exceeds the permissible value, the drive unit will
come to trip (depends on Pr. 502).
Valid only Mitsubishi drive unit (computer link operation) protocol
9999
If a communication error occurs, the drive unit will not come to trip.
(NET operation mode at initial value)
122
PU communication
check time interval
0
0
RS-485 communication can be made. Note that a communication
fault (E.PUE) occurs as soon as the drive unit is switched to the
operation mode with command source. (NET operation mode at
initial value)
0.1 to 999.8s
Communication check (signal loss detection) time interval
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)
502
Stop mode
selection at
communication
error
0
At fault
occurrence
Indication
Fault
output
At fault removal
0 Coasts to stop E.PUE Output
Stop
(E.PUE)
1
Decelerates to
stop
After stop
E.PUE
Output
after stop
Stop
(E.PUE)
2
Decelerates to
stop
After stop
E.PUE
Without
output
Automatic restart
functions
3
Continues
running at Pr. 779
—
Without
output
Operates in normal
condition
779
Operation speed
during
communication
error
9999
0 to 12000r/min/
0 to 8000r/min
∗1∗2
Motor runs at the specified speed at a communication error.
9999 Motor runs at the speed used before the communication error.
The above parameters can be set when Pr. 160 Extended function display selection = "0". (Refer to page 144)
∗1 Differs according to capacities. (0.2K to 2.2K/3.7K)
∗2 If a value exceeding 3000r/min is set, the actual rotation speed will be limited at 3000r/min.
