Terms, Definitions and Abbreviations Used in This Manual User Manual PROFview XL
Terms, Definitions and Abbreviations Used in this Manual
Baud rate
Data transfer rate (1 baud = 1 bit/s)
Differential voltage
is the voltage between the RS485 signal lines A (pin 8) and B (pin 3)
U
D
= U
B
- U
A
Disturbance-free voltage
range
The term 'disturbance-free voltage range' is used to denote a voltage range of the differential voltage
for a selected station over the whole frame, whose limits are not violated - not even momentarily - over
the evaluation period.
DMF
Device master file; description of the technical data of a PROFIBUS device
DSO
Digital storage oscilloscope
Evaluation period
10/16th of the bit width around the bit center (RS485 transceiver-sample point), within which the distur-
bance-free voltage range is measured
Firmware
Software for a microprocessor
FPGA
Field Programmable Gate Array – programmable logic array for real-time functions
Idle
Bus condition or transmission break between two successive frames
ID number
Device code of a PROFIBUS device used for assignment to the device master file (DMF).
Illegal frames
Frames which do not conform to IEC 61158-3 (with protocol errors)
Master
Active bus station (usually the PLC) coordinating the access to the bus
Relevant frame
The term 'relevant frame' is used if a frame contains the source address of the bus station to be mea-
sured (or the short acknowledgment following a request frame issued to this station)
Segment
PROFIBUS section terminated on both line ends using a powered resistor combination. A repeater
which is either inserted between line ends or else connected to one line end also constitutes a seg-
ment termination.
Slave
Bus station which as a rule only sends to the bus upon request by the master (e.g. digital I/O)
Token
Frame (SD4) which is exchanged between the active stations (masters) to control the access to the
PROFIBUS
VIII PROFview XL
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