Mitsubishi Electric FR-A820-00046 Instruction Manual page 791

Parameters
[Parameters related to communication with the RS-485 terminals]
Pr.
331
N030
332
N031
N032
N033
333
334
N034
335
N035
336
N036
337
N037
341
N038
When "1" (MODBUS RTU protocol) is set in Pr. 549, the setting range within parentheses is applied.
When a value outside the setting range is set, the inverter operates at the initial value.
In the MODBUS RTU protocol, the data length is fixed at 8 bits.
In the MODBUS RTU protocol, Pr. 334 setting is applied as the stop bit length. (Refer to page 5-630.)
In the MODBUS RTU protocol, this is invalid.
NOTES The monitored items and parameter settings can be read during communication with the Pr. 336
"RS-485 communication check time interval"= "0 (initial value)" setting, but such operation will
become faulty once the operation mode is changed to the NET operation mode. When the NET
operation mode is selected as the start-up operation mode, communication is performed once,
then a Communication fault (inverter) (E.SER) occurs. To perform operation or parameter writing
via communication, set "9999" or a large setting value in Pr. 336. (The setting value is determined
by the computer program.) (Refer to page 5-620.)
Always reset the inverter after making the initial settings of the parameters. After changing the
communication-related parameters, communication cannot be made until the inverter is reset.
FR-A800
Initial
Name
value
RS-485 communication
station number
RS-485 communication
speed
RS-485 communication
data length
RS-485 communication
stop bit length
RS-485 communication
stop bit length / data
length
RS-485 communication
parity check selection
RS-485 communication
retry count
RS-485 communication
check time interval
RS-485 communication
9999
waiting time setting
RS-485 communication
CR/LF selection
(N) Operation via communication and its settings
Setting
Description
range
0 to 31
Set the inverter station number.
(0 to 247)
0
(Same specifications as Pr. 117)
3, 6, 12, 24,
48, 96, 192, Select the communication speed.
96
384, 576, (Same specifications as Pr. 118)
768, 1152
Select the data length.
0 0, 1
(Same specifications as P.N022)
Select the stop bit length.
1 0, 1
(Same specifications as P.N023)
Select the stop bit length and data bit 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)
0 to 10, Set the permissible number of retries for unsuccessful
1
9999 data reception. (Same specifications as Pr. 121)
RS-485 communication is available, but the inverter trips
0
in the NET operation mode.
0.1 to Set the interval of the communication check (signal loss
0 s
999.8 s detection) time. (Same specifications as Pr. 122)
9999 No communication check (signal loss detection)
0 to 150 Set the waiting time between data transmission to the
ms, 9999 inverter and the response. (Same specifications as Pr. 123)
Select the presence/absence of CR/LF.
1 0, 1, 2
(Same specifications as Pr. 124)
5 - 611