Technical data
Communication time
Processing time 820X
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EDSMF2133IB EN 5.0
4.3 Communication time
The communication time is the time between the start of a request and the arrival of the
corresponding response.
The communication times depend on ...
ƒ the processing time in the controller
ƒ the transmission delay time
– the baud rate
– the telegram length
4.3.1 Processing time 820X
For the 820X series several processing steps are required in the controller, which are
processed cyclically.
A processing cycle consists of:
ƒ Writing of control word or setpoint if the value has changed;
ƒ Alternating reading of status word and actual value;
ƒ Processing of parameter accesses if there is a job.
If the processing time caused by cyclic reading of the status word/actual value is too large,
the alternating reading of status word and actual value can be suppressed. This is
controlled by bit 15 (process input data inhibit) of the DRIVECOM control word:
ƒ Process input data inhibit = 0: Status and actual value update active
ƒ Process input data inhibit = 1: Status and actual value update not active
A suppression of the processing of parameter accesses is not necessary, since this is
controlled by the user.
In the following table the times for the processing steps are listed:
Processing step Max. processing time in [ms]
Process input data
inhibit = 0
Tolerance Process input data
inhibit = 1
Tolerance
Read parameter 55 +48 55 +8
Control word or setpoint 27 +48 27 +8
Control word and
setpoint
54 +56 54 +16
Write parameter 108 +32 − −
Status word and actual
value
200 +40 200 −
) Note!
A setpoint sign reversal also results in writing the control word.