Communication System Manual
3WN6 Circuit-Breakers
Version 1.0 (05/98)
Copyright Siemens AG 1998. All rights reserved.
55
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
Message
address
Time response of communication
(Duration of read/write operations
and update rate for values in 3WN6)
0:x
Circuit-breaker key data
x =
1
Test unit + delivery date
500, 1, 0, 0, 0
2
Identifier number
500, 2, 0, 0, 0
The data in messages 0:1 to 0:16 are read-only.
4
Rated current of circuit-
breaker
500, 4, 0, 22, 0
The PLC takes approx. 530 ms to read these values
out of 3WN6.
5
Function test of release
500, 5, 0, 0, 0
The circuit-breaker key data are updated within
the 3WN6 circuit-breaker approx. every 60 s.
11
Circuit-breaker size
502, 1, 0, 0, 0
Note: The update rate defines the maximum "age" of
12
Circuit-breaker type
502, 2, 0, 0, 0
any value read from 3WN6.
13
No. of poles
502, 3, 0, 0, 0
14
Version of release unit (in
ASCII code)
502, 4, 0, 0, 0
15
Revision level of
communication
502, 5, 0, 0, 0
16
Communication module
version
502, 6, 0, 0, 0
17
Revision level of release unit
