Siemens SIMATIC ET 200S Installation And Operating Manual page 183

Safety-related communication
Safety-related communication is used to exchange fail-safe data.
Sensor Evaluation
There are two types of sensor evaluation:
-> 1oo1 evaluation - Sensor signal is read in once
-> 1oo2 evaluation - Sensor signal is read in twice from the same F-module and compared
internally
Sensors
Sensors permit exact acquisition of digital and analog signals and exact measurement of
routes, positions, velocities, rotational speeds, weights, etc.
Standard Mode
Operating mode of F-I/O, in which standard communication is possible but not -> safety-
related communication by means of safety message frames.
Fail-safe signal modules of S7-300 can be used in standard mode or -> safety mode. Fail-
safe modules of ET 200S are designed for safety mode only.
Static Parameter
Static parameters can only be set when the CPU is in STOP mode and cannot be changed
by means of SFC (system function) while the user program is running.
Terminal Module
The ET 200S distributed I/O system is terminated with the terminal module. If a terminal
module is not inserted, the ET 200S is not ready for operation.
Voltage Bus (P1/P2)
Voltage buses (P1 and P2) are two internal buses that supply the electronic modules with
voltage. The voltage buses are fed by the power module and are connected by means of the
terminal module.
Voltage Group
A voltage group is a group of electronic modules supplied by a power module.
ET 200S Distributed I/O System - Fail-Safe Modules
Hardware Installation and Operating Manual, 07/2005, A5E00103686-04
Glossary
Glossary-9