Workstation" Application - Bosch Rexroth ID 40 Manual

7.9.3

"Workstation" application

This example is for a workstation with a lift positioning unit. Since a link cannot be
established between the SLK and the MDT when the workpiece pallet is raised, data
is exchanged in two stages.
Stage 1: Reading the workpiece-specific data to check whether or not this workpiece
can be processed at this station. The data is read from the MDT in an event-oriented
manner. The SLK then automatically switches to DISCONNECTED. Only when the lift
positioning device lowers after processing does the SLK switch to CONNECTING.
This eliminates the risk of an unexpected break in communication as the MDT
approaches the SLK from above.
Stage 2: Entering measurement data obtained while the workpiece was being
processed. Only the pretransmit function is used here.
SLK preparation
An unbuffered prefetch is configured that transmits both the MDT status (see
Chapter 4.3.2.1 "MDT status register") and the control data (e.g., 16 bytes as of
MDT address 0x0024) in the event-oriented data channel. The SLK switches to auto
disconnect mode and the link state switches to CONNECTING.
No. Command-oriented data
exchange
1 Begin setting parameters
for unbuffered prefetch
2 Delete unbuffered
prefetch if any data
blocks are entered
3 Set parameters for first
data block in unbuffered
prefetch: 1-byte MDT
status
4 Set parameters for
second data block in
unbuffered prefetch:
16 bytes starting from
MDT address 0x0024
5 Finish setting param-
eters for unbuffered
prefetch. Prefetch is
now active
6 Switch SLK to auto
disconnect mode
7 Make SLK ready to
receive (CONNECT)
8 Wait until event counter in event-oriented data channel (see Chapter 7.3.1 "Status informa-
tion in event-oriented data channel") to increase by 1. At this point, a workpiece pallet has
arrived, the event-oriented data is valid and the link is DISCONNECTED. The MDT status and
control data can be checked and the workpiece pallet can be raised.
CMD Data0 Data1 Data2
0x0B 0x00
0x0B 0x04
0x01 0x00 0x02 0x00
0x01 0x00 0x00 0x00
0x0B 0x01
0x06 0x00 0x03 0x00
0x06 0x00 0x03 0x00
3 842 530 344/2014-05, MIT: ID 40, Bosch Rexroth AG
PROOF COPy 1 | 20.05.2014 | FOR INTERNAL USE ONLy
Profibus DP 63/176
Data3 Data4 Data5 Data6
0x00 0x00 0x01
0x24 0x00 0x10
0x02 0x00 0x01 0x02
0x01 0x00 0x01 0x01