Technical data

Communication
9.4 Communication via PROFINET IO
Function Manual
Function Manual, 06/2012, 6SL3097-4AB10-0BP4
671
Setting criteria for times
Cycle (T
DC
)
T
DC
must be set to the same value for all bus nodes. T
DC
is a multiple of SendClock.
T
DC
> T
CA_Valid
and T
DC
≧ T
IO_Output
T
DC
is thus large enough to enable communication with all bus nodes.
T
IO_Input
and T
IO_Output
Setting the times in T
IO_Input
and T
IO_Output
to be as short as possible reduces the dead
time in the position control loop.
T
IO_Output
> T
CA_Valid
+ T
IO_Output_MIN
Settings and optimization can be done via a tool (e.g. HWConfig in SIMATIC S7).
User data integrity
User data integrity is verified in both transfer directions (IO controller <––> IO device) 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.
IO controller sign of life
STW2.12 ... STW2.15 are used as the IO controller sign of life.
The IO controller sign-of-life counter is incremented in each IO controller application
cycle (T
CACF
).
The number of sign-of-life errors tolerated can be set via p0925.
p0925 = 65535 deactivates sign-of-life monitoring on the IO device.
Monitoring
The IO controller sign of life is monitored on the IO device and any sign-of-life errors
are evaluated accordingly.
The maximum number of tolerated IO controller 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:
1. A corresponding message is output.
2. The value "0" is output as the IO device sign of life.
3. A new synchronization with the IO controller sign of life is started.
IO device sign of life
ZSW2.12 ... ZSW2.15 are used as the IO device sign of life.
The IO device sign-of-life counter is incremented in each DC cycle (T
DC
).