234
Communication operation and setting
4.19.7 Modbus-RTU communication specifications
(Pr. 331, Pr. 332, Pr. 334, Pr. 343, Pr. 502, Pr. 539, Pr. 549, Pr.779)
Using the Modbus-RTU communication protocol, communication operation or parameter setting can be
performed from the RS-485 terminals of the inverter.
Parameter
Number
Name
Initial
Value
Setting Range
Description
331
RS-485
communication
station number
0
0
Broadcast communication is selected.
1 to 247 *
Specifies the inverter station number.
Set the inverter station numbers when two or more inverters
are connected to one personal computer.
332
RS-485
communication
speed
96
3, 6, 12, 24, 48,
96, 192, 384 *
Set the communication speed.
The setting value
×
100 equals the communication speed.
For example, the communication speed is 9600bps when
the setting value is "96".
334
RS-485
communication parity
check selection
2
0
Without parity check
Stop bit length 2 bits
1
With odd parity check
Stop bit length 1 bit
2
With even parity check
Stop bit length 1 bit
343
Communication error
count
0
⎯
Displays the number of communication errors during
Modbus-RTU communication. Reading only
502
Stop mode selection
at communication
error
0
At Fault
Occurrence
Indication
Fault Output
At Fault
Removal
0
Coasts to
stop.
E.SER
Output
Stop
(E.SER)
1
Decelerates
to stop
After stop
E.SER
Output after
stop
Stop
(E.SER)
2
Decelerates
to stop
After stop
E.SER
Without
output
Automatic
restart
functions
3
Continues
running at
Pr.779
⎯
Without
output
Operates in
normal
condition
539
Modbus-RTU
communication check
time interval
9999
0
Modbus-RTU communication is available, but the inverter
trips in the NET operation mode.
0.1 to 999.8s
Set the interval of communication check time.
(same specifications as
Pr. 122
)
9999
No communication check (signal loss detection)
549
Protocol selection
1
0
Mitsubishi inverter (computer link) protocol
1
Modbus-RTU protocol
2
BACnet MS/TP protocol
779
Operation frequency
during
communication error
9999
0 to 400Hz
Motor runs at the specified frequency at a communication
error.
9999
Motor runs at the frequency used before the communication
error.
The above parameters can be set when
Pr. 160 User group read selection
= "0".
...
Specifications differ according to the date assembled.
to check the SERIAL number.
* The inverter works with the initial parameter setting if a value other than the setting range is set.
CAUTION
When Modbus-RTU communication is performed from the master with address 0 (station 0) set, broadcast communication is
selected and the inverter does not send a response message to the master.
When response from the inverter is necessary, set a value other than "0" in
Pr. 331
.
Some functions are invalid for broadcast communication.
REMARKS
⋅
When using the Modbus-RTU protocol, set
Pr. 549 Protocol selection
to "1".
⋅
When the communication option is fitted with
Pr. 550 NET mode operation command source selection
set to "9999" (initial value), the
command source (e.g. run command) from the RS-485 terminals is invalid.
Summary of Contents for -NAFR-F720-00167-NA
Page 22: ...12 MEMO ...
Page 364: ...354 MEMO ...
Page 378: ...368 MEMO ...
Page 396: ...386 MEMO ...