Technical data

Table Of Contents
SFCs for Distributed I/Os or PROFINET IO
System Software for S7-300/400 System and Standard Functions - Volume 1/2
16-12
A5E00709327-01
Activating DP Slaves/PROFINET IO devices
When you reactivate a DP slave/PROFINET IO device with SFC 12, this compoent
is configured and assigned parameters by the designated DP master/PROFINET
IO controller (as with the return of a failed DP station/PROFINET IO station). This
activation is completed when the component is able to transfer user data.
Activating a DP slave/PROFINET IO device does not start the program error OB
(OB85), even if its inputs or outputs belong to the system-side process image to be
updated. An entry in the diagnostic buffer is also not made.
Activating a DP slave/PROFINET IO device does not start the rack failure OB
(OB86), and the operating system also does not make an entry in the diagnostic
buffer.
If you attempt to use SFC 12 to activate a slave which has been deactivated and is
physically separated from the DP bus, after approx. 1 minute the SFC will return
the error code W#16#80A2. The slave remains deactivated. If the slave is
reconnected to the DP bus at a later time, it must be reactivated with SFC12.
Note
Activating a DP slave/PROFINET IO device may be time-consuming. Therefore, if
you wish to cancel a current activation job, start SFC 12 again with the same value
for LADDR and MODE = 2. Repeat the call of SFC 12 until successful cancellation
of the activation is indicated by RET_VAL = 0.
If you wish to activate DP slaves which take part in the cross communication, we
recommend that you first activate the transmitters and then the receivers
(listeners).
CPU Startup
Depending on the startup mode, the CPU operating system behaves as follows
regarding DP slaves/PROFINET IO devices:
In the startup modes cold and warm restart, slaves/devices are activated
automatically.
In the hot restart mode, the slaves/devices activation status remains
unchanged, that is, activated slaves/devices remain activated and deactivated
slaves/devices remain deactivated.
After the CPU start-up, the CPU cyclically attempts to contact all configured and
not deactivated slaves/devices that are either not present or not responding.
Note
The startup OBs do not support the call of SFC 12.