Functions - Siemens SIMATIC PCS 7 Function Manual

5.2.3

Functions

Overview
The figure below provides an overview of the "FB_SACT" block function:
How it works
At a request from the OS, the "FB_SACT" block reads the current actual values of the storage
locations from the AS and sends these as a data cell to the requesting OS using the
"FB_UA_WM" block.
At the input parameters "IN_DB01" to "IN_DB25", the OS specifies the "FB_STOR" instance
data blocks of the storage locations from which actual values are to be read. If the actual values
of fewer than 25 storage locations are requested, the OS writes "0" to the "IN_DB..." inputs
that are not required.
The OS defines the actual values to be read with specifications at the input parameters
"IN_FOR01" to "IN_FOR10" and "IN_OFF01" to "IN_OFF10". The "IN_OFF..." parameter
specifies the position of the required actual value in the status area of the instance DB of the
corresponding "FB_STOR" block. The "IN_FOR.." parameter is used to calculate the volume
of data to be read.
You can also query the status of individual binary values in a data word. The "IN_OFF..."
parameter specifies the position of the data word in the instance DB, and the "IN_CNT..."
parameter (binary value position) defines the bit to be queried (= 0 to 15).
The number of actual values to be read is specified by the OS with the "IN_COUNT" parameter.
Up to 10 actual values can be queried from each of a maximum of 25 storage locations.
Advanced Process Functions (APF)
Function Manual, 07/2016, A5E38719883-AA
Storage location management
5.2 FB_SACT
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