Siemens ET 200S Manual page 553

Potential group
A group of electronic modules supplied by a power module.
Power buses (P1/ P2)
Two internal buses (P1 and P2) that supply the electronic modules with voltage.
The power buses are fed by the power module and connected by means of the
terminal modules.
Prewiring
The wiring of the terminal modules before the electronic modules are inserted.
Process image
The process image is a component of the system memory of the DP master. The
signal states of the input modules are transferred to the process-image input area
at the beginning of the cyclic program. At the end of the cyclic program, the values
of the process-image output area are transferred to the DP slave as the signal
states.
Process-related modules
Modules that are equipped with technological functions, such as counting pulses,
positioning, and controlling stepping motor power units.
PROFIBUS
PROcess FIeld BUS, a German process and field bus standard defined in
IEC 61784-1:2002 Ed1 CP 3/1. It defines the functional, electrical, and mechanical
properties of a bit-serial field bus system.
PROFIBUS is available with the protocols DP (which stands for distributed
peripherals, that is, distributed or remote I/O), FMS (which stands for field bus
message specification), PA (= process automation), or TF (= technology
functions).
Distributed I/O System ET 200S
EWA 4NEB 780 6024-02 07
Glossary
Glossary-5