Fail-Safe Function Block F_Scale_Dint; Introduction; Connections; Inputs - Siemens Simatic Manual

Fail-safe function blocks for storage and retrieval machines

3.3 Fail-safe function block F_SCALE_DINT

3.3.1

Introduction

Fail-safe function block F_SCALE_DINT, together with an associated block in the standard program
(SCALE_DINT), scales a DINT value from the process image to a 16 bit value with unit SLU. The ac-
tual scaling itself is realized in the standard program; the result is safely transferred into the F part of
the CPU. This scaling, i.e. specifying the scaling factor for example is parameterized using block
F_SCALE_DINT in the safety program; the same is true for the plausibility check as to whether the
scaled value was correctly transferred from the standard part into the F part.
The value scaled by the standard SCALE_DINT block is made available to the safety program after a
plausibility check using this block.
3.3.2

Connections

All bool variables listed in the following tables are preassigned FALSE, all integer variables are preas-
signed 0 – and all word variables preassigned W#16#0.
3.3.2.1

Inputs

Name
SCALE_Z
SCALE_N
LADDR_IO
MASK_OFFSET
MASK_LENGTH
INSTANCE_ID
S7-Distributed Safety/SIMATIC Safety - fail-safe function blocks for storage and retrieval machines
Data type Description
Numerator, scaling factor
This value is used for scaling and adapting the direction of
Int
the raw encoder value from the process image to the unit
SLU
Denominator, scaling factor
Int This value is used for scaling the raw encoder value from the
process image to the unit SLU
Peripheral address
Int The address of the encoder from HW Config should be inter-
connected here, whose raw value should be scaled.
Masking, bit offset
Int Position of the first valid bit of the position actual value in the
raw encoder value
Masking, bit length
Int Length of the position actual value in the encoder raw value
in bits
Number instance DB
The number of the instance DB of the block call is parameter-
Int
ized at this input. This parameter is required to check the
plausibility of the data transfer between F_SCALE_DINT and
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