ProSoft Technology 5205-DFNT-PDPS - Manual (Page 17)

Functional Overview PDPS ♦ ProLinx Gateway
PROFIBUS DP Slave
ProSoft Technology, Inc. Page 17 of 61
December 31, 2008
2.3 Module Internal Database
Central to the functionality of the module is the internal database. This database
is shared between all the ports on the module and is used as a conduit to pass
information from one device on one network to one or more devices on another
network. This permits data from devices on one communication port/network to
be viewed and controlled by devices on another port/network. In addition to data
from the slave port, status and error information generated by the module can
also be mapped into the internal database.
2.3.1 PROFIBUS Slave Port Access to Database
The Slave driver uses the database in two ways:
1 A read command issued to a slave device by the slave driver will return the
slave data into the internal database.
2 A write command issued to a slave device by the slave driver uses the data in
the internal database to write to the slave device
Besides the standard PROFIBUS interface reserved Database range from word
0 to word 399, the PDPS driver recognizes a special command code in the
PROFIBUS protocol that causes the PDPS driver to write to, or read from the
Database range word 400 to word 3999. This feature opens up to the user the
whole capacity of the PDPS module's Database.
To use the Database Paging functionality in the PDPS driver the following three
items must be implemented.
1 Enable the paging feature in the PDPS module's configuration file under the
[Profibus Slave] section, set Use Database Paging : Y.
2 In PROFIBUS Master module's configuration the PROFIBUS Slave must be
set to 100 Input Words and 100 Output Words.