Theory Of Operation - G&L MMC-A2 Hardware Manual

8.4

Theory of Operation

The Profibus scanner module provides a memory image of the nodes (slaves)
connected to a Profibus network. It is this memory image that is controlled
by your LDO created in PiCPro. The module's on-board processor
continually transfers data between this memory image and the actual
Profibus nodes.
Communication between the Profibus module and the nodes can be set
between 9600 baud (1200m max.) and 12M baud (100m max.). The baud
rate, the relationship between the memory image and specific data in each
node, and other parameters are established with configuration software run in
an external PC.
This configuration software generates two files. One file is downloaded to
the Profibus module through its RS232 serial port. The other file is used by
PiCPro to establish the relationship between the memory image and the
declared variables in the LDO. To ensure that a given location in the memory
image is connected to a variable in the LDO and to the corresponding data in
the Profibus node, the same tag name or label must be used.
For example, when running the configuration software, PROX_SW1 could
be used as the name for a boolean bit of a Profibus Block I/O. It would
correspond to the wiring location of a proximity switch. The name
PROX_SW1 must also be used for the corresponding variable in your LDO.
The Profibus scanner module provides DP master Class 1 functionality only.
This includes DP multi-master support (token) passing and cyclic slave
communications. It does not support DP master Class 2, sync and freeze
modes, nor extended DP functions.
The G&L Motion Control Profibus configuration software (G&L
Motion Control Part No. M.1300.7794) is required to configure the
Profibus scanner (within the Profibus module) for the devices on the
associated network.
Additional information about Profibus can be obtained at www.profi-
bus.com
G & L Motion Control Inc.
MMC Profibus Option Module
NOTE
NOTE
MMC Hardware Manual 139