West Control Solutions KS98-1 - Manual (Page 189)

III-14 Description of KS 98-1 CAN bus extension
There are various modes for KS 98-1 communication via the CAN bus. The unit can be master for handling the NMT
services (NMT = Network ManagemenT), or slave, can send or receive PDOs (PDO = process data object) cyclically or
send SDO telegrams asynchronously (SDO = service data object). A KS98-1 can contact any bus parties simultaneously
with other KS98-1, allocated remote IOs, KS800 multi-controllers and up to 40 sensors or actuators, and via asyn -
chronous telegrams. Max. 42 CAN nodes can be addressed.
KS 98-1 handles guarding tasks as a master or a slave with an own local RM node. Display is in the CAN status win -
dow. However, there are limits to the performance of the bus parties and the bus itself. The dynamic operations of the
bus can be evaluated only by statistics. The resulting bus and interface load of an instrument is dependent on the de -
tails of the communication structure and can be estimated only, if the behaviour of the individual parties is known ex -
actly. In the following, properties and effects of various bus parties are explained and figures and facts are presented.
Information on the COB-IDs consumed internally at PMA is given in the annex. This information should be taken into
account when adding instruments from other manufacturers.
9499-040-82711 Description of KS 98-1 CAN bus extension
III-189
device n
Data-producer
Transmit
SDO telegram SDO operator
-PDO
device m
Data-receiver
Receive-PDO
Process Data Objects (PDO)
Process data for fast exchange
- one party sending = all parties can read
(Producer / consumer concept)
max. 8 bytes for data / message
non-confirmed message
snchronous or event-triggered
Priority control via address
Instrument-specific data contents
Service Data Objects (SDO)
for data without real-time requirement
asynchronous, confirmed messages
Repartition over several telegrams is pos-
sible
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