Communication Eeprom Write Selection (Pr. 342) - Mitsubishi Electric FR-F740-00023-EC Instruction Manual

Communication operation and setting
[RS-485 terminal communication related parameter]
Parameter
Number
RS-485 communication station
331
number
332 RS-485 communication speed
RS-485 communication stop bit
333
*2
length
RS-485 communication parity
334
check selection
RS-485 communication retry
335
*3
count
RS-485 communication check
336
*3
time interval
RS-485 communication waiting
337
*3
time setting
RS-485 communication CR/LF
341
*3
selection
549 Protocol selection
*1 When "1" (Modbus-RTU protocol) is set in Pr. 549, the setting range within parenthesis is applied.
*2 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 page 179)
*3 The Modbus-RTU protocol becomes invalid.
*4 The Modbus-RTU protocol is valid for only communication from the RS-485 terminals.
*5 The above parameters can be set when Pr. 160 User group read selection = "0". (Refer to page 146)
CAUTION
⋅ 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 173)
⋅ 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.

3.18.4 Communication EEPROM write selection (Pr. 342)

Parameters written via the inverter's PU connector, RS-485 terminals, or from the communication option can be
Pr.341
written to the RAM. Set this parameter when frequent parameter changes are required.
page 167
Pr.343
page 179
Parameter
Number
Communication EEPROM write
342
selection
The above parameters can be set when Pr. 160 User group read selection = "0".
option is connected.
⋅ When changing the parameter values frequently, set "1" in Pr. 342 to write them to the RAM. The life of the EEPROM will
be shorter if parameter write is performed frequently with the setting unchanged from "0 (initial value)" (EEPROM write).
REMARKS
⋅ When Pr. 342
is set to
Therefore, the parameter values available when power is switched on again are the values stored in EEPROM previously.
168
Name
Name
(Refer to page 146)
"1" (only RAM write)
, the new values of the parameters will be cleared at power supply-off of the inverter.
Initial
Setting Range
Value
0 to 31 (0 to 247)
0
*1
3, 6, 12, 24, 48,
96
96, 192, 384
1 0, 1, 10, 11
2 0, 1, 2
1 0 to 10, 9999
0
0s
0.1 to 999.8s
9999
0 to 150ms,
9999
9999
1 0, 1, 2
0
0
1
Setting
Initial Value
Range
0
0
1
However, it can be set any time when the communication
Description
Set the inverter station number. (same
specifications as Pr. 117)
Used to select the communication speed.
(same specifications as Pr. 118)
Select stop bit length and data length. (same
specifications as Pr. 119)
Select the parity check specifications. (same
specifications as Pr. 120)
Set the permissible number of retries at
occurrence of a data receive error.
(same specifications as Pr. 121)
RS-485 communication can be made, but the
inverter will come to an alarm stop in the NET
operation mode.
Set the interval of communication check time.
(same specifications as Pr. 122)
No communication check
Set the waiting time
transmission to the inverter and response.
(same specifications as Pr. 123)
Select presence/absence of CR/LF.
(same specifications as Pr. 124)
Mitsubishi inverter (computer link) protocol
Modbus-RTU protocol
*4
Description
Parameter values written by communication are
written to the EEPROM and RAM.
Parameter values written by communication
are written to the RAM.
between data