Technical data

R911305038 / 01 | Rexroth VCP-Operating Concept Electric Drives and Controls | Bosch Rexroth AG 6-99
DIN Measurement Bus
6.7.4 DIN Measurement Bus Slave
You can operate up to 30 slave terminals simultaneously on one DIN
Measurement Bus. The slave terminals access the data of the bus
master. All of the slave terminals function in the same way as when
directly connected to a controller. You only have to adjust the interface
parameters to the DIN Measurement Bus.
The bus master (process computer or gateway to PLC) and slave are
connected via the DIN Measurement Bus, as specified in DIN 66348.
The services required for data exchange (user data of the DIN Measu-
rement Bus protocol) are defined in an own specification.
To reduce the workload on the bus, each slave terminal may have its
own read-only data cache. The address location and length of the
cache are negotiated during synchronization between the bus master
and slave terminal. The bus master performs an equidistant transfer of
the cache data by broadcasting them to all slave terminals and each
slave terminal then saves this data locally.
If a slave terminal has a read request that is located within this cache
area, no communication process takes place via the gateway to the
PLC. Instead, the data is copied locally from the terminal cache.
Variables that are output just once and are contained within the cache
area are output again once the next cache package is received. Since
the gateway performs an equidistant transfer of cache data, this means
that a rapid output with higher priority can be executed (independently
of the general output cycle).
6.7.5 Programming
6.7.5.1 Protocol Parameters for the DIN Measurement Bus Slave
You can use the protocol parameters to influence the communication
between the operating device and the controller. All parameters are set
to the default values which ensure a reliable communication.