Initial Settings And Specifications Of Rs-485 Communication - Mitsubishi Electric FR-A820-00046 Instruction Manual

(N) Operation via communication and its settings
5.15.4

Initial settings and specifications of RS-485 communication

Use the following parameters to perform required settings for the RS-485 communication between
the inverter and a personal computer.
● There are two types of communication, communication using the inverter's PU connector and
communication using the RS-485 terminals.
● Parameter setting, monitoring, etc. can be performed using Mitsubishi inverter protocol and
MODBUS RTU communication protocol.
● To make communication between the personal computer and inverter, setting of the communi-
cation specifications must be made to the inverter in advance.
Data communication cannot be made if the initial settings are not made or if there is any setting
error.
[Parameters related to PU connector communication]
Pr.
117
N020
118
N021
N022
N023
119
120
N024
121
N025
122
N026
123
N027
124
N028
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Initial
Name
value
PU communication
station number
PU communication
speed
PU communication data
length
PU communication stop
bit length
PU communication stop
bit length / data length
PU communication
parity check
Number of PU
communication retries
PU communication
9999
check time interval
PU communication
9999
waiting time setting
PU communication CR/
LF selection
Setting
Description
range
Specify the inverter station number.
0 0 to 31
Set the inverter station numbers when two or more
inverters are connected to one personal computer.
Set the communication speed.
48, 96, 192,
The setting value × 100 equals the communication speed.
192 384, 576,
For example, if 192 is set, the communication speed is
768, 1152
19200 bps.
0 Data length 8 bits
0
1 Data length 7 bits
0 Stop bit length 1 bit
1
1 Stop bit length 2 bits
0 Stop bit length 1 bit
1 Stop bit length 2 bits
1
10 Stop bit length 1 bit
11 Stop bit length 2 bits
0 Without parity check
2 1 With parity check at odd numbers
2 With parity check at even numbers
Set the permissible number of retries for unsuccessful
0 to 10 data reception. If the number of consecutive errors
1
exceeds the permissible value, the inverter will trip.
9999 If a communication error occurs, the inverter will not trip.
0 No PU connector communication
Set the interval of the communication check (signal loss
detection) time.
0.1 to
999.8 s
If a no-communication state persists for longer than the
permissible time, the inverter will trip.
9999 No communication check (signal loss detection)
Set the waiting time between data transmission to the
0 to 150 ms
inverter and the response.
9999 Set with communication data.
0 Without CR/LF
1 1 With CR
2 With CR/LF
Parameters
Data length 8 bits
Data length 7 bits