Operation Selection At Communication Error Occurrence (Pr. 121, Pr. 122, Pr. 502) - Mitsubishi Electric FR-E720-600 Instruction Manual

Communication operation and setting

4.20.3 Operation selection at communication error occurrence (Pr. 121, Pr. 122, Pr. 502)

You can select the inverter operation when a communication line error occurs during RS-485 communication from the
PU connector.
Parameter
Name
Number
Number of PU
121 communication
retries
PU communication
122
check time interval
Stop mode selection
502 at communication
error
The above parameters can be set when Pr. 160 User group read selection = "0". However, it can be set any time when the communication option is connected.
(Refer to page 180)
(1) Retry count setting (Pr.121)
Set the permissible number of retries at data receive error occurrence. (Refer to page 212 for data receive error for retry)
When data receive errors occur consecutively and exceed the permissible number of retries set, an inverter trips (E.PUE)
and a motor stops (as set in Pr. 502).
When "9999" is set, an inverter fault is not provided even if data receive error occurs but an alarm signal (LF) is output.
For the terminal used for the LF signal output, assign the function by setting "98 (positive logic) or 198 (negative logic)" in
any of Pr. 190 to Pr. 192 (output terminal function selection).
Example: PU connector communication, Pr. 121 = "1" (initial value)
Computer
Inverter
Inverter
Computer
Example: PU connector communication, Pr. 121 = "9999"
Computer
Inverter
Inverter
Computer
LF
REMARKS
Pr. 121 is valid only when Mitsubishi inverter (computer link operation) protocol is selected. Pr. 121 is not valid when Modbus-
RTU communication protocol is selected.
204
Initial Setting
Value Range
0 to 10
1
9999
0
0.1 to
0
999.8s
9999
0, 3
0
1
2
Wrong
Reception error
Wrong
OFF
Description
Number of retries at data receive error occurrence If the number of
consecutive errors exceeds the permissible value, the inverter will
come to trip (depends on Pr. 502).
Valid only Mitsubishi inverter (computer link operation) protocol
If a communication error occurs, the inverter will not come to trip.
RS-485 communication can be made. Note that a communication
fault (E.PUE) occurs as soon as the inverter is switched to the
operation mode with command source.
Communication check (signal loss detection) time interval
If a no-communication state persists for longer than the permissible
time, the inverter will come to trip (depends on Pr. 502).
No communication check (signal loss detection)
At fault
Indication
occurrence
Coasts to stop E.PUE
After stop
Decelerates to
stop
E.PUE
After stop
Decelerates to
stop E.PUE
Fault (E. PUE)
Wrong
Reception error
Wrong
Reception error Reception error
ON
At fault
Fault output
removal
Stop
Output
(E.PUE)
Output after Stop
stop (E.PUE)
Automatic
Without output restart
functions
Normal
OFF