Mitsubishi Electric FR-A700 Technical Manual page 438

(7) Signal loss detection [Pr. 122, 539]
If a signal loss (communication stop) is detected in
the signal loss detection performed between the
inverter and computer, communication error (E.SER
in , E.PUE in
A700 F700
and the inverter output is shut off. (It depends on the
[Pr. 502] setting in
E700
A signal loss detection is made when the setting is
any of 0.1 to 999.8s. To make a signal loss detection,
it is necessary to send data from within the
communication check time interval.
When the setting is 9999, communication check
(signal loss detection) is not made.
If communication is broken due to signal cable
breakage, computer fault etc., the inverter does not
Example: [Pr. 539 = 0.1 to 999.8s]
Query communication
Operation mode
Programmable
controller (master)
Inverter (slave)
Inverter (slave)
Programmable
controller (master)
[Pr.539]
Communication
check counter
Broadcast communication
Operation mode
Programmable
controller (master)
Inverter (slave)
Inverter (slave)
Programmable
controller (master)
[Pr.539]
Communication
check counter
) occurs,
E700 D700
.)
D700
A700
External NET
Query Message1
Data absence time
(3.5 bytes or more)
Response Message1
Check start
External NET
Query Message1 Query Message2
Data absence time
(3.5 bytes or more)
Check start
detect such a fault. This should be fully noted.
It is recommended to set the communication check
time interval before starting operation to prevent
hazardous conditions.
When the setting is 0 in
and parameter
communication
operation mode is switched to the Network operation
mode.
When the setting is 0 (initial value) in
communication from RS-485 can be performed,
however, communication error (E.PUE) would occur
if switched to another operation mode with command
source (NET mode at initial setting).
Query Message2
Fault
(E.SER)
Response Message2
Time
Fault
(E.SER)
Time
472
PARAMETER
, monitoring
A700 F700
read are available.
error (E.SER) would
E700
However,
occur if
,
D700