Glossary-4
Communications Processor CP 541
EWA 4NEB 812 6188-02
Draft standard PROFIBUS DP (DIN E 19245, Part 3) on which the distrib-
uted periphery (I/O) system is based.
The main task of PROFIBUS DP is fast cyclic exchange of data between the
central DP master and the peripherals.
R
You specify the duration of the response delay time with the configuring soft-
ware of the DP master.
If a DP slave is not addressed within the response monitoring time, it goes to
the safe state and all outputs are set to 0.
The CP 541 sends a zero message to the connected programmable controller.
S
Send Data with Acknowledge: SDA is a service used in PROFIBUS. The
addressed station confirms reception of the message.
Send Data with No Acknowledge: the SDN service is used in SINEC L2 if a
station wishes to send a message to two or more other stations. The addressed
stations do not confirm reception of the message.
SINEC L2 is a bus system for the networking of PROFIBUS-compatible au-
tomation systems and field devices in the cell and field level. SINEC L2 is
available with the following protocols: PLC-PLC, DP (distributed periphery
(I/O)), FDL (fieldbus data link), FMS (fieldbus message specification) and
TF (technological functions).
The SINEC L2 bus system with the DP protocol
A slave may only exchange data with a master when requested to do so by
the master.
Send and Request Data: SRD is a service used in PROFIBUS. The addressed
station confirms reception of the message or sends the requested data.
A station is a device which can send, receive or amplify data via the bus; for
example, master, slave, repeater, transceiver.
PROFIBUS DP
Response Delay
Time
SDA
SDN
SINEC L2
SINEC L2-DP
Slave
SRD
Station
Glossary