![ProSoft Technology InRax MVI71-DNPSNET Скачать руководство пользователя страница 61](http://html1.mh-extra.com/html/prosoft-technology/inrax-mvi71-dnpsnet/inrax-mvi71-dnpsnet_user-manual_1618934061.webp)
Reference MVI71-DNPSNET
♦
PLC Platform
Distributed Network Protocol Interface Module
ProSoft Technology, Inc.
Page 61 of 100
September 22, 2008
Data Flow Between MVI71-DNPSNET Module and the PLC Processor
The following topics describe the flow of data between the two pieces of
hardware (PLC processor and MVI71-DNPSNET module) and other nodes on
the DNP network for the block-transfer interface. Data is automatically moved
between the module and the processor when the side-connect interface is
employed. The DNP Server Driver allows the MVI71-DNPSNET module to
respond to data read and write commands issued by a master on the DNP
network. The following flow chart and associated table describe the flow of data
into and out of the module.
Step Description
1
The configuration information for the module is retrieved from the DNPSNET.CFGfile on
the Compact Flash Disk. This information configures the module and define the Ethernet
node characteristics.
2
A Host device (DNP Master unit) issues a read or write command to the module's node
address. The driver qualifies the message before accepting it into the module.
3
After the module accepts the command, the data is immediately transferred to or from
the appropriate internal database in the module. If the command is a read command, the
data is read out of the database and a response message is built. If the command is a
write command, the data is written directly into the database and a response message is
built.
4
After the data processing has been completed in Step 3, the response is issued to the
originating master node.
5
Counters are available in the Status Block that permit the ladder logic program to
determine the level of activity of the Slave Driver.
6
The module constantly monitors for command control blocks from the processor. If a
valid block is received, the function is executed. Additionally, data is constantly being
exchanged between the module and the processor.
Review the
Module Configuration
section for a complete list of the parameters
that must be defined for a slave port.
Содержание InRax MVI71-DNPSNET
Страница 4: ......