Programming
Fail-Safe Systems
5-2 A5E00085588-03
5.1.2 Blocks of the Safety Program
Fail-Safe Blocks
A Safety Program can contain the following fail-safe blocks:
• Fail-safe blocks that can be inserted by the user (F user blocks)
F User Blocks Function
F-Driver
F_CH_DI
F_CH_AI
F_CH_DO
Channel driver for the input and output signals of the F-I/Os
Conversion
F_BO_FBO
F_I_FI
F_R_FR
F_TI_FTI
Conversion from standard to F-data types
F_FBO_BO
F_FI_I
F_FR_R
F_FTI_TI
Conversion from F to standard data types
F_QUITES Fail-safe acknowledgment via the ES/OS
F_FR_FI Conversion from F_REAL to F_INT.
RTG – RTG
Communication
F_S_BO, F_S_R
F_R_BO, F_R_R
Communication between F-run-time groups
CPU – CPU
Communication
F_SENDBO,
F_SENDR
F_RCVBO, F_RCVR
Communication with Safety Programs on other CPUs
F_START Signals a cold restart or warm restart.