Hitachi SJ Series User Manual page 497

Chapter 14
14.2.4 Communication process
A

Communication process
Communication between external control equipment and
the inverter is carried out in the following process:
External control
equipment
Inverter
(Silent interval of at least [3.5 character times])
<Adjusted with communication waiting time [CF-07]>
①Frame sent from external control equipment to the
inverter (query)
②Frame returned from the inverter to external control
equipment (response)
③After the inverter sends a response, if a query from the
hose is not completely received within the time set in
[CF-06] (communication timeout time), the inverter will be
in the condition of receiving the head data again. During
this, the inverter will be in a no response condition and
will behave as set in the communication error selection.
For more details, see the following.
Parameter
Item
Communication error
selection
Communication
timeout time
Communication
waiting time
①
Waiting time
Parameter Data
00:Trip
01:Trip after stopping
02:Ignore
[CF-05]
03:Free-run stop
04:Deceleration stop
[CF-06] 0.00~100.00(s)
[CF-07] 0.~1000.(ms)
②
③Communication trip time
(When reception is timed-out, the
inverter behaves in accordance with the
communication error selection.)
Monitoring of reception timeout begins following the
completion of first transmission after the power supply is
turned ON or reset. A reception timeout does not occur until
a transmission is performed.
A response from the inverter (frame ②) is output as a reply
after the inverter receives a query (frame ①) and hence is
not output actively.
Trip with error [E041] after reception timeout.
Deceleration stop after reception timeout.
Trip with error [E041] after stopping.
No trip, nor alarm output.
No free-run stop trip, nor alarm output after
reception timeout.
No deceleration stop, nor alarm output after
reception timeout.
The time until reception timeout.
Waiting time until a reply starts after completion of
receiving (excluding silent interval).
14-6
RS485 Communication
①
Time
Description