Siemens SIMATIC NET PROFIBUS, Owner'S Manual

Page: 484 / 490

Glossary
Glossary-4
PROFIBUS Networks SIMATIC NET
6GK1970-5CA20-0AA1 Release 2 05/2000
Max_T
SDR
Max_T
SDR
is a bus parameter and specifies the maximum protocol processing
time of the responding node (station delay responder).
Min_T
SDR
Min_T
SDR
is a bus parameter and specifies the minimum protocol processing
time of the responding node (station delay responder).
Node
A device that can send and receive data on PROFIBUS as a master or slave.
Optical power budget (FO)
This is available between a sender and receiver on a fiber-optic link. It indicates
the difference between the optical power coupled into a particular fiber by the
optical transmitter and the input power required by an optical receiver for reliable
signal detection.
Optical power loss (FO)
The optical power loss is the cumulative value of all the losses occurring in the
fiber-optic transmission path. These are due mainly to the attenuation of the fiber
itself and the splices and couplings. The optical power loss must be less than the
optical power budget available between the transmitter and receiver.
PROFIBUS
PROcess FIeld BUS, European process and fieldbus standard specified in the
PROFIBUS standard (EN 50 170, Volume 2, PROFIBUS).
This specifies the functional, electrical and mechanical characteristics of a bit-se-
rial fieldbus system.
PROFIBUS is a bus system that networks PROFIBUS-compatible automation
systems and field devices at the cell and field level. PROFIBUS exists with the
DP protocol (= Distributed Peripheral I/Os), FMS protocol (= Fieldbus Message
Specification) or PA protocol (= Process Automation).
PROFIBUS address
To identify it uniquely, every station must be assigned a PROFIBUS address.
A PC/PG or the ET 200 Handheld have the PROFIBUS address ”0”.
Master and slaves have a PROFIBUS address in the range 1 to 125.