Measures In The User Program - Siemens SIMATIC PROFINET Function Manual

5.12.6

Measures in the user program

Introduction
You can make certain changes in the user program to accelerate the startup for IO devices
of docking systems that alternate during operation.
Making the required changes to the user program
To accelerate the startup by making changes to the user program, follow these steps:
1. Call the "D_ACT_DP" instruction to activate and deactivate the IO device at the start of
the OB 1 cycle.
If the IO device is replaced, the device that is no longer required must be deactivated and
the new device must be activated.
2. If you control the "Power ON" command of the IO devices via the application, then start
the activation of the IO devices via the corresponding call of the "D_ACT_DP" instruction
as near to the same time as possible. The IO device has to be physically connected for
this.
3. You access the IO device using direct access commands after the "D_ACT_DP"
instruction has provided the feedback "IO device activated".
PROFINET with STEP 7 V14
Function Manual, 09/2016, A5E03444486-AG
Functions
5.12 Accelerating startup
241