Mitsubishi Electric FR-A500 Instruction Manual page 137

<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 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.
Communication request is sent to the inverter
1)
in accordance with the user program.
2) Inverter data processing time
Reply data from
the inverter(Data 1)
3)
is checked for
error)
4) Computer processing delay time
Answer from
computer in
5) response to reply
data 3)(Data 3) is
checked for error)
* 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 130.)
(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
[Data format]
Format A
Format A'
[Data read]
Format B
Computer
↓
(Data flow)
Inverter
Inverter
*
1
↓
(Data flow)
Computer
Operation
Command
No error* (Request
accepted)
With error (request
rejected)
No error*
(No inverter
processing)
With error.
Inverter outputs
3) again.
*2 Inverter
*1 Instruction
station Waiting
code
ENQ
number time
1 2 3 4 5
*2 Inverter
*1 Instruction
station Waiting
ENQ code
number time
1 2 3 4 5
*2 Inverter
*1 Instruction
station Waiting
ENQ code
number time
1 2 3 4 5
Data read
*
2
1)
2) 3)
Data write
Run Running Parameter
Frequency
A' A
Present Present
C C
D D
Absent Absent
Absent Absent
Absent Absent
*3
Sum
Data
check
6 7 8 9 10 11
*3
Sum
Data *4
check
← Number of characters
6 7 8 9 10 11
*3
Sum
*4
check
← Number of characters
6 7 8 9
128
PARAMETERS
4) 5)
Time
Inverter
Monitoring
Write Reset
A A
Present Absent Present
C Absent
D Absent
Absent Absent
Absent Absent
Absent Absent
*4
12 13 ← Number of characters
Parameter
Read
B B
Present
E
E
E'
F F
Absent Absent
G G
H H