62/176 Profibus DP
Bosch Rexroth AG, MIT: ID 40, 3 842 530 344/2014-05
7.9.2 “Outfeed” application
Outfeed points are where it is decided whether or not the workpiece pallet is
diverted. The workpiece pallets do not need to stop at the SLK before the junction,
since the amount of data needed for the decision is small. In this example, 32 bytes
should be read starting at MDT address 0x02F0. The MDT status is also transmitted
in order to allow any errors in the MDT to be addressed.
The data is read from the MDT through an unbuffered prefetch, then the link
immediately switches from PRECONNECTED to CONNECTING, since auto reconnect is
active.
SLK preparation
No. Command-oriented data
exchange
CMD Data0 Data1 Data2 Data3 Data4 Data5 Data6
1 Begin setting parameters
for unbuffered prefetch
0x0B 0x00
2 Delete unbuffered
prefetch if any data
blocks are entered
0x0B 0x04
3 Set parameters for first
data block in unbuffered
prefetch: 1-byte MDT
status
0x01 0x00 0x02 0x00 0x00 0x00 0x01
4 Set parameters for
second data block in
unbuffered prefetch:
32 bytes starting from
MDT address 0x02F0
0x01 0x00 0x00 0x02 0xF0 0x00 0x20
5 Finish setting param-
eters for unbuffered
prefetch. Prefetch is
now active
0x0B 0x01
6 Switch SLK to auto
reconnect mode
0x06 0x00 0x03 0x00 0x02 0x00 0x01 0x01
7 Make SLK ready to
receive (CONNECT)
0x06 0x00 0x03 0x00 0x01 0x00 0x01 0x01
SLK operation
Wait until event counter in event-oriented data channel (see Chapter 7.3.1 “Status
information in event-oriented data channel”) to increase by 1.
At this point:
• A workpiece pallet has arrived
• Event-oriented data exchange with the MDT has occurred
• The link for the next MDT is back to CONNECTING
• The MDT status and the system data can be checked
The requested data bytes are sent to the fieldbus master through the event-oriented
data exchange for every MDT. The data can be provided for additional evaluation
using a controller function block.
PROOF COPY 1 | 20.05.2014 | FOR INTERNAL USE ONLY
To Next Page
Loading...
