Glossary of Profibus terms
PROFIBUS, like many other networking systems, has a set of unique terminology. Table below contains a
few of the technical terms used in this guide to describe the PROFIBUS interface. They are listed in
alphabetical order.
Address (Station)
IEC 61158-2: Medium attachment unit identification - unique
number of a station connected to a segment (participant).
Address Space
Within PROFIBUS DP the maximum possible number of
addressable network nodes per segment, e.g. 127.
Alarm
Notification of an abnormal or unexpected event within a
system. Alarms in PROFIBUS DP require in addition to the
standard diagnosis event mechanism within the cyclic data
exchange a separate acyclic acknowledgement procedure
between a host and a Slave application. Since DP-V1, "Device
related diagnosis" is the basis for the "Alarm" and "Status"
types of diagnosis events (GSD: "DPV1"=1). PROFIBUS DP
defines the following alarm types: Diagnosis, Status, Process,
Update, Pull and Plug Alarm. See "Device Related Diagnosis".
The PNO maintains a Profile Guideline, Part3: Diagnosis,
Alarms and Time Stamping, order no. 3.522.
Alert
Alert is a generic term for two different types of notifications
within a PROFIBUS DP/PA network especially arranged but not
exclusively for the process automation:
•
alarm;
•
event.
Both alert types may be used with or without a user
acknowledgement mechanism. The PNO maintains a PROFIBUS
guideline "Time Stamp", order no. 2.192.
Application Profile
Within PROFIBUS a specified agreement within families of
field devices on how to use the general PROFIBUS
communication platform and its subsystems (e.g. device
integration via GSD, EDD, FDT/DTM and Communication
Function Blocks). Communication profiles are not a part of the
PROFIBUS DP application profiles. See "Profile".
Baud rate (Data Rate)
Other common terms are "data transfer rate" and
"transmission rate". Within PROFIBUS DP this is the amount of
data transferred across a fieldbus segment per second. A data
rate is measured in units of bits per second ( "b/s" or "bps"), or
baud.
Bus Cycle
The period of time the bus Master needs to poll every
participant (Slave) once. More bus Masters can be activated by
using the token principle which consequently prolong the bus
cycle.
Class
See “DP Master”, “DP Master Class 1 (DPM1)” and “DP Master
