Fail-Safe Blocks
Fail-Safe Systems
A5E00085588-03
8-35
8.4 Blocks for Converting Data
Block Description
F_BO_FBO Convert from BOOL to F_BOOL
F_I_FI Convert from INT to F_INT
F_R_FR Convert from REAL to F_REAL
F_TI_FTI Convert from TIME to F_TIME
F_FBO_BO Convert from F_BOOL to BOOL
F_FI_I Convert from F_INT to INT
F_FR_R Convert from F_REAL to REAL
F_FR_FI Convert from F_REAL to F_INT
F_FTI_TI Convert from F_TIME to TIME
F_QUITES Fail-safe acknowledgment via the ES/OS
!
Safety Note – Use F_LIM_R for plausibility check of standards to F-data
conversion
The F_BO_FBO, F_I_FI, F_TI_FTI and F_R_FR blocks only carry out data
conversion. This means you must program additional measures for plausibility
checks in the Safety Program, for example using F_LIM_R, to ensure that only
safe operation is possible.
Plausibility Checking
The simplest form of plausibility check is to specify a range with fixed upper and
lower limits, e.g. with the F_LIM_R block. Not all the input parameters can be
checked for plausibility simply enough. These input parameters cannot be
modified during operation.
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