Mitsubishi FR-A800

(N) Operation via communication and its settings
570
PARAMETERS
Retry count setting (Pr.121, Pr.335)
• Set the permissible number of retries at data receive error occurrence. (Refer to page 569 for data receive error for retry.)
• When the data receive errors occur consecutively and the number of retries exceeds the permissible number setting, a
communication fault (PU connector communication: E.PUE, RS-485 terminal communication: E.SER) occurs and the
inverter trips.
• When a data transmission error occurs while "9999" is set, the inverter does not trip but outputs the alarm (LF) signal.
To use the LF signal, set "98 (positive logic) or 198 (negative logic)" in any of Pr.190 to Pr.196 (output terminal function
selection) to assign the function to an output terminal.
NOTE
• For the RS-485 terminal communication, the operation at a communication error occurrence depends on the Pr.502 Stop
mode selection at communication error setting. (Refer to page 560)
Computer
Example: PU connector communication, Pr. 121 = "1" (initial value)
Example: PU connector communication, Pr. 121 = "9999"
Reception error Reception error
Fault (E.PUE)
Inverter
Computer
Inverter
Computer
Inverter
Computer
Inverter
ENQ
ACK NAK NAK
LF OFF
OFF
ENQ
ACK NAK NAK
ON ON
Illegal
Illegal
ENQ
ACK
Normal
ENQ
Illegal
ENQ
Illegal
Reception error
Reception error
ALM
ON
ALM