Siemens DP/AS-Interface Link 20E Manual page 156

Glossary
DP mode
In communication between the DP master and the DP slaves, a distinction is
made between the following four modes:
– OFFLINE
– STOP
– CLEAR
– RUN
Each of these modes is characterized by defined actions between the DP master
and DP slave.
DP slave
A –> station with slave functions in –> PROFIBUS DP.
Firmware
In this case, the software running on the DP/AS–Interface Link 20E.
FREEZE mode
The FREEZE mode is a DP mode in which process data can be acquired from
one, or several (group) or from all DP slaves at the same time. The point at
which the data is acquired is indicated by the FREEZE command (this is a con-
trol frame for synchronization).
Maximum station delay
A –> bus parameter for –> PROFIBUS. The Maximum Station Delay (max.
TSDR) specifies the longest time required by one of the –> stations in a –> sub-
net between receiving the last bit of an unacknowledged –> frame to sending the
first bit of the next frame. A sender must wait until the max. TSDR has elapsed
after sending an unacknowledged frame before it can send a further frame.
Minimum Station Delay
A –> bus parameter for –> PROFIBUS. The Minimum Station Delay (min. TSDR)
specifies the minimum time that the receiver of a –> frame must wait before sen-
ding the confirmation or sending a further frame. The min. TSDR is based on the
longest time required by a station in the sub system to receive a confirmation
after sending the frame.
MPI
The multipoint interface (MPI) is the PG interface of SIMATIC S7.
PROFIBUS
A field bus complying with EN 50170, Vol. 2. Previous name: SINEC L2.
156
DP/AS-Interface Link 20E
Release 11/2002
C79000-G8976-C138–04