Instruction manual

124
PARAMETERS
* When you have set write to RAM, powering off the inverter clears the parameter values that
have been changed. Therefore the parameter values available when power is switched on
again are those stored previously in E
2
PROM.
When the parameter values will be changed frequently, set "1" in Pr. 342 to choose write to
RAM. Performing frequent parameter write with "E
2
PROM write" set will shorten the life of the
E
2
PROM.
The Pr. 342 " E
2
PROM write selection" setting is also valid when the communication option is
fitted.
<Computer programming>
(1) Communication protocol
Data communication between the computer and inverter is performed using the
following procedure:
*1. If a data error is detected and a retry must be made, execute retry operation with the
user program. The inverter comes to an alarm stop if the number of consecutive
retries exceeds the parameter setting.
*2. On receipt of a data error occurrence, the inverter returns "reply data 3)" to the
computer again. The inverter comes to an alarm stop if the number of consecutive
data errors reaches or exceeds the parameter setting.
122
Communication
check time
interval
0 No communication
0.1 to
999.8
Set the communication check time [seconds] interval.
If a no-communication state persists for longer than the
permissible time, the inverter will come to an alarm stop.
9999 Communication check suspension
123
Waiting time
setting
0 to 150
Set the waiting time between data transmission to the
inverter and response.
9999 Set with communication data.
124
CR • LF
instruction
presence/
absence
0 Without CR/LF
1 With CR, without LF
2With CR/LF
342*
E
2
PROM write
selection
0
When parameter write is performed from the
computer, parameters are written to E
2
PROM.
1
When parameter write is performed from the
computer, parameters are written to RAM.
REMARKS
When parameter is set to without E
2
PROM write (Pr.342="1"), performing power
reset or terminal reset returns the setting value to the original value (value stored in
E
2
PROM).
Parameter
Number
Name Setting Description
Data read
Data write
1) 5)4)
3)
2)
*1
*2
↓ (Data flow)
Inverter
Inverter
Time
Computer
Computer
↓ (Data flow)
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