Mitsubishi Electric FR-A700 Instruction Manual page 626

Communication operation and setting
RS-485 terminal communication related parameter
Pr. No. Name
RS-485 communication
331
station
RS-485 communication
332
speed
RS-485 communication
333
stop bit length
RS-485 communication
334
parity check selection
RS-485 communication
335
retry count
RS-485 communication
336
check time interval
RS-485 communication
337
waiting time setting
RS-485 communication
341
CR/LF selection
549
Protocol selection
When "1" (Modbus-RTU protocol) is set in Pr. 549, the setting range within parenthesis is
applied.
For the Modbus-RTU protocol, the data length is fixed to 8 bits and the stop bit depends on
the Pr. 334 setting. (Refer to section 6.23.6.)
The Modbus-RTU protocol becomes invalid.
The Modbus-RTU protocol is valid for only communication from the RS-485 terminals.
NOTES If communication is made without Pr. 336 "RS-485 communication check time interval"
being changed from "0" (initial value), monitor, parameter read, etc. can be performed, but
the inverter results in an alarm as soon as it is switched to the NET operation mode. If the
operation mode at power on is the network operation mode, a communication alarm
(E.SER) occurs after first communication.
When performing operation or parameter write through communication, set "9999" or more
to Pr. 336. (The setting depends on the computer side program.) (Refer to page 6-456.)
Always reset the inverter after making the initial settings of the parameters. After you have
changed the communication-related parameters, communication cannot be made until the
inverter is reset.
6 - 446
Initial Setting
Description
Value Range
0–31
Set the inverter station number.
0
(same specifications as Pr. 117)
(0–247)
Used to select the communication
3/6/12/24/
96 48/96/192/ speed.
384
(same specifications as Pr. 118)
Select stop bit length and data length.
1 0/1/10/11
(same specifications as Pr. 119)
Select the parity check specifications.
2 0/1/2
(same specifications as Pr. 120)
Set the permissible number of retries
1 0–10/9999 at occurrence of a data receive error.
(same specifications as Pr. 121)
RS-485 communication can be made,
0 but the inverter will come to an alarm
stop in the NET operation mode.
Set the interval of communication
0 s
0.1–999.8s check time.
(same specifications as Pr. 122)
9999 No communication check
Set the waiting time between data
transmission to the inverter and
0–150ms/
9999
9999
response.
(same specifications as Pr. 123)
Select presence/absence of CR/LF.
1 0/1/2
(same specifications as Pr. 124)
Mitsubishi inverter (computer link)
0
protocol
0
1
Modbus-RTU protocol
Parameter
Refer to
Parameters referred to
Section
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