Time Response Of Data Traffic - Siemens 3VF Series Communications Manual

Communication System Manual

3.4.5 Time response of data traffic

The time response of 3WN6 data traffic via PROFIBUS-DP is outlined in detail on the following
pages with reference to the different data which are transferred (acyclic, cyclic, circuit-breaker key
data, circuit-breaker functions ...). Please note that the PROFIBUS-DP cycle times which are implicit
in the specified time values generally depend on the number of slaves, i.e. values can vary.
This simple rule of thumb generally applies: To read
approx. 0.5 seconds, to write approx. 1 second, to write
and check approx. 2 seconds.
The various items of data present in 3WN6 are updated at different intervals depending on their
importance.
Time response of acyclic data traffic:
Message group 0
T-Nr. Designation
0:x Circuit-breaker key data
x =
1 Test unit + delivery date
2 Identifier number
4 Rated current of circuit-
breaker
5 Function test of release
11 Circuit-breaker size
12 Circuit-breaker type
13 No. of poles
14 Version of release unit (in
ASCII code)
15 Revision level of
communication
16 Communication module
version
17 Revision level of release unit
Version 1.0 (05/98)
Message
Time response of communication
address
(Duration of read/write operations
and update rate for values in 3WN6)
500, 1, 0, 0, 0
500, 2, 0, 0, 0
The data in messages 0:1 to 0:16 are read-only.
500, 4, 0, 22, 0 The PLC takes approx. 530 ms to read these values
out of 3WN6.
500, 5, 0, 0, 0 The circuit-breaker key data are updated within
the 3WN6 circuit-breaker approx. every 60 s.
502, 1, 0, 0, 0
Note: The update rate defines the maximum "age" of
502, 2, 0, 0, 0 any value read from 3WN6.
502, 3, 0, 0, 0
502, 4, 0, 0, 0
502, 5, 0, 0, 0
502, 6, 0, 0, 0
© Copyright Siemens AG 1998. All rights reserved.
3WN6 Circuit-Breakers
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