MITSUBISHI ELECTRIC FR-S520 - Manual (Page 129)

120
(1) Communication protocol
Data communication between the computer and inverter is performed using the
following procedure:
Data read
Data write
1) 5) 4)
3) 2)
*1
*2
Computer
(Data flow)
Inverter
Computer
(Data flow)
Inverter
Time
REMARKS
*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.
(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
Monitor-
ing
Parame-
ter Read
1)
Communication request
is sent to the inverter in
accordance with the
user program in the
computer.
A' A (A")*1 A (A")*2 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")*1
E
(E")*2
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
(Absent)
G
(Absent)
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 from the computer to the inverter, 10ms or
more is also required after "no data error (ACK)". (Refer to page 123.)