Siemens SINAMICS S120 Function Manual page 420

Communication PROFIBUS DP/PROFINET IO
10.2 Communication via PROFIBUS DP
Per byte of user data
One additional class 2 master
User data integrity
User data integrity is verified in both transfer directions (master <––> slave) by a sign-of-life
(4-bit counter).
The sign-of-life counters are incremented from 1 to 15 and then start again at 1.
● Master sign-of-life
● Slave sign-of-life
420
Data
– STW2.12 ... STW2.15 are used for the master sign-of-life.
– The master sign-of-life counter is incremented in each master application cycle
(TMAPC).
– The number of sign-of-life errors tolerated can be set via p0925.
– p0925 = 65535 deactivates sign-of-life monitoring on the slave.
– Monitoring
The master sign-of-life is monitored on the slave and any sign-of-life errors are
evaluated accordingly.
The maximum number of tolerated master sign-of-life errors with no history can be set
via p0925.
If the number of tolerated sign-of-life errors set in p0925 is exceeded, the response is
as follows:
– A corresponding message is output.
– The value zero is output as the slave sign-of-life.
– Synchronization with the master sign-of-life is started.
– ZSW2.12 ... ZSW2.15 are used for the slave sign-of-life.
– The slave sign-of-life counter is incremented in each DP cycle (T
Time required [µs]
Function Manual, (FH1), 07/2007 Edition, 6SL3097-2AB00-0BP4
1,5
500
).
DP
Drive Functions