Mitsubishi FR-A500 Series - Page 134

PARAMETERS
121
<Computer programming>
(
1
)
Communication protocol
Data communication between the computer and inverter is performed using the following procedure:
*
1
*
2
Computer
Inverter
↓ (Data flow)
Computer
↓ (Data flow)
Inverter
Data read
Data write
Time
1)
2) 3)
4)
5)
*1. If a data error is detected and a retry must be made, execute retry operation from 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.
(
2
)
Communication operation presence/absence and data format types
Communication operation presence/absence and data format types are as follows:
No. Operation
Run
Command
Running
Frequency
Parameter
Write
Inverter
Reset
Monitoring
Parameter
Read
1)
Communication request is sent to the
inverter in accordance with the user
program.
A’ A A A B B
2) Inverter data processing time Present Present Present Absent Present Present
No error*
(Request accepted)
C C C Absent
E
E’
E
3)
Reply data from the
inverter
(Data 1) is checked
for error)
With error
(request rejected)
D D D Absent F F
4) Computer processing delay time Absent Absent Absent Absent Absent Absent
No error*
(No inverter
processing)
Absent Absent Absent Absent G G
5)
Answer from
computer in response
to reply data 3)
(Data 3) is checked
for error)
With error.
Inverter outputs 3)
again.
Absent Absent Absent Absent H H
* In the communication request data given from the computer to the inverter, 10ms or more is also
required after "no data error (ACK)". (Refer to page 123)
(
3
)
Data format
Hexadecimal data is used. Data is automatically transferred in ASCII between the computer and inverter.
1) Data format types
(1) Communication request data from computer to inverter
*3
ENQ
*4
123456789101112
13
*3
ENQ
*4
1234567891011
*3
ENQ
*4
123456789
[Data format]
Format A
[Data read]
Format A'
Format B
Inverter
station
number
Instruction
code
*5
Waiting
time
Data
Sum
check
Inverter
station
number
Inverter
station
number
Instruction
code
Instruction
code
*5
Waiting
time
*5
Waiting
time
Data
Sum
check
Sum
check
←Number of characters
←Number of characters
←Number of characters
4