66
Process Image
WAGO-I/O-SYSTEM 750
753-668/000-004 4FAI 0/4-20 mA Diff PROFIsafe
Manual
Version 1.0.0, valid from HW/SW Version 01/01
5
Process Image
The F I/O module 753-668/000-004 occupies 14 data bytes in the input process
image and 5 data bytes in the output process image in the higher-level safe PLC.
The safe PROFIsafe telegrams to send and receive are stored in input bytes
0
… 13 and in output bytes 0 … 4.
The process image contains different data depending on whether the
F I/O module is operated in PROFIsafe Mode V2.4 or PROFIsafe Mode V2.6.
Only use safety-related process values transmitted via PROFIsafe!
Process values received via communication paths other than the safe protocol
may not be used in a safety-related manner.
Channel status must be evaluated!
The channel status bits indicate whether a channel is error-free (channel status
bit = 1) or has been passivated due to an error (channel status bit = 0), see
Section “PROFIsafe Mode V2.4” and “Channel Status Byte”. It is not possible to
use the process value to clearly determine whether a channel is error-free
because the safe substitute value can have the same value as a valid process
value. The channel status must therefore be evaluated or linked to the process
value. If a channel status bit indicates an error, appropriate measures must be
taken.
The F parameters are used to set the PROFIsafe mode!
The F parameters are used to set the respective PROFIsafe mode (V2.4 or
V2.6), see Section “Appendix” > … > “PROFIsafe F Parameters”.