Siemens SIMATIC S7 Functional Safety Manual page 201

ES
Engineering System (ES): An engineering system is a PC-based configuration system that
enables convenient, visual adaptation of the process control system to the task at hand.
Fail-safe
A system or component designed to reliably provide a defined, safe result in the event of a
fault.
F-DI, F-DQ DC, and F-RLY
The manual uses the following short names for the S7-1200 fail-safe SMs:
● F-DI: SM 1226 DI 16 x 24 VDC
● F-DQ DC: SM 1226 DQ 4 x 24 VDC
● F-RLY: SM 1226 DQ 2 x Relay
F-FBs /F-FCs
Fail-safe function blocks (FB) and function calls (FC) are program units in which you
program the safety program in F-FBD or F-LAD. FBs include an instance DB (Data Block)
that retains information about that particular usage of the function in your program. For
example, each specific instance of a timer has a DB to retain the results of each timer
update. FCs do not include an instance DB, and no information is carried over between calls
to FCs.
F-I/O
A general term for fail-safe input and output signal modules (SM).
F-monitoring time
The F-monitoring time is the amount of time an SM or CPU waits for an error-free
communication including the expected new Virtual Monitoring Number before passivating
channels.
F-runtime group
An F-runtime group consists of an F-OB (cycle OB or cyclic interrupt OB) that calls a main
safety block (FB or FC). Additional user-specific safety functions must then be called from
this main safety block.
F-system
A fail-safe system.
S7-1200 Functional Safety Manual
Manual, 02/2015, A5E03470344-AA
Glossary
201