Updating Process Image Partitions In The User Program - Siemens SIMATIC S7-1500 System Manual

9.8.2

Updating process image partitions in the user program

Requirements
Alternatively, you can also use the following instructions to update process images:
• "UPDAT_PI" instruction
• "UPDAT_PO" instruction
You will find the instructions in STEP 7 in the "Instructions" task card under "Extended
instructions" in the "Process image" folder. You can call the instructions from any point in the
user program.
Requirements for updating process image partitions with the "UPDAT_PI" and "UPDAT_PO"
instructions:
• The process image partitions must not be assigned to any OB. This means the process
image partitions are not automatically updated.
Note
Update of PIP 0
PIP 0 (automatic update) cannot be updated with the "UPDAT_PI" and "UPDAT_PO"
instructions.
UPDAT_PI: Updates the process image partition of the inputs
With this instruction, you read the signal states from the input modules of the IO devices to
the process image partition of the inputs (PIPI).
UPDAT_PO: Updates the process image partition of the outputs
With this instruction, you transfer the process image partition of the outputs of the IO devices
to the output modules.
Direct I/O access to the inputs and outputs of the IO devices
You also have direct read and write access to the I/O as an alternative to access via the
process image, should direct access be required for programming reasons. Direct (write) I/O
access also writes to the process image. This prevents a subsequent output of the process
image from again overwriting the value written by direct access.
Additional information
You can find more information on process image partitions in the Cycle and response times
(https://support.industry.siemens.com/cs/ww/en/view/59193558) function manual.
SIMATIC Drive Controller
System Manual, 11/2023, A5E46600094-AD
9.8 Process images and process image partitions
Configuring
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