ProSoft Technology 5201-DFNT-DH485 - Manual (Page 13)

Functional Overview DH485 ♦ ProLinx Gateway
Driver Manual DH485 Interface
ProSoft Technology, Inc.
Page 13 of 44
August 27, 2009
The module supports the common interface file (CIF) of the DH-485 protocol. A
separate data area can be defined for each application port. This data area is
divided into read and write data and is mapped into the module’s internal
database. The module’s application constantly transfers the read CIF data from
the CIF database to the module database and the write CIF data from the
module to the CIF database. The parameters used to define the CIF database
are contained in the configuration file. This optional feature of the module should
only be utilized if required by a remote master on the network. Otherwise, the
data file functions (500CPU message) instructions should be used to access and
control the module’s data. The following diagram shows the relationship of the
DH-485 drivers, the CIF database and the module’s database:
Parameter Value Format
Read Register Start 600 Word
Read Register Count 600 Word
Write Register Start 0 Word
Write Register Count 600 Word
CIF Read DB Offset 1200 Byte
CIF Read Count 144 Byte
CIF Write DB Offset 0 Byte
2.2.2 DH-485 CIF Information
The following illustration shows four different uses and configurations of the CIF
data area:
Read CIF Data Area
0
.
.
243
Example #1
CIF Read DB Offset:
CIF Read Count:
CIF Write DB Offset:
1000
244
-1