Siemens SIMATIC S7 F User Manual

Programming
Fail-Safe Systems
5-62 A5E00085588-03
5.4.12 Changing Fail-Safe Constants in CFC Test Mode
It is possible in CFC test mode (V5.2 and above) to change fail-safe constants
(non-interconnected I/Os of fail-safe blocks) during operation (RUN). In the case of
safety programs, this is only permitted when safety mode is deactivated. There are
no restrictions on changing standard parameters.
Rules for Changing Fail-Safe Constants
• In the case of parameters in the safety data format, you can only change the
DATA components, not COMPLEM or PARID.
• You must not change output parameters and automatically supplied I/Os.
Prerequisites
Before you switch on CFC test mode, make sure that the following prerequisites
are met:
• The CPU must be in RUN.
• Safety mode of the Safety Program must be deactivated. If it is not, you will be
requested to deactivate safety mode when you try to change the first
parameter.
Note
Changing fail-safe constants in safety mode will always result in a safe state
(Safety Program disabled).
To change fail-safe constants, you must enter the F password. The password is
the same one used for the compilation and downloading of changes. Irrespective of
the protection level set for the CPU, it might be necessary to provide legitimation
for the online connection to the CPU.

Siemens SIMATIC S7 F Specifications

General

Brand	Siemens
Model	SIMATIC S7 F
Category	Controller
Language	English