Technical data

6-94 Bosch Rexroth AG | Electric Drives and Controls Rexroth VCP-Operating Concept | R911305038 / 01
DIN Measurement Bus
6.7.1.2 Cache Function for Read-Only Data
The cache function reads a memory area of up to 62 bytes from the
PLC and broadcasts the information to all connected slaves at cyclic
intervals. This greatly reduces the load on the bus and allows simulta-
neous transmission of the data to all operating devices.
The broadcast service on communication layer 2 is not monitored,
therefore, the slaves implement a definable timeout to monitor receipt
of the broadcasted data packets.
If a slave has a read request which is located within the cache area, no
communication will be carried out via the gateway to the PLC, but the
data will be copied locally from the cache of the gateway operating
device.
Variables that are displayed once and which are located within the
cache area, will be displayed once more after receipt of the next cache
packet. The gateway operating device transmits the cache data in an
equidistant fashion thus permitting a high-priority and speedy output
which is independent of the general output cycle.
6.7.1.3 Network Status
A 4-byte area is used by the gateway to transmit the status of the net-
work to the PLC. Each slave which is detected on the network and
Function "Activate/deactivate LEDs"
Data 0 LED 1 to LED 4
Data 1 LED 5 to LED 8
Data 2 LED 9 to LED 12
Data 3 LED 13 to LED 16
Data 4 LED 17 to LED 20
Data 5 LED 21 to LED 24
Data 6 LED 25 to LED 28
Data 7 LED 29 to LED 32
Data 8 LED 33 to LED 36
Data 9 LED 37 to LED 40
Data 10 LED 41 to LED 44
Byte Bit Function
Fig. 6-144: Function of the individual bytes