PTQ DNPS App Ref Guide

PTQ-DNPS ♦ Quantum / Unity Platform

Distributed Network Protocol Interface Module

Reference

What does "Initialize Output Data" in the configuration file mean?

The default of this user parameter is NO. When the module reboots it will reset all of its internal registers to a zero value. In some applications this will cause a problem as the master wishes to see what he/she believes he/she put in that register during the last access. If this is true you should set this parameter to

YES, which will cause the module to convert the writes (command function 2) in the [BACKPLANE DATA EXCHANGE] section to reads for one scan and one scan only. This will reload the registers in the module with the information contained within the PLC.

Where do the individual data types actually exist in the modules memory?

The placement of the individual data types is in a pre-defined order, which is the same as they are placed in the configuration file for easy reference. They will be placed in memory sequentially as follows:

ƒ

Binary

ƒ

Analog

ƒ Counter

ƒ Binary

ƒ

Analog

When you describe the database in the DNPS configuration file you should create sufficient data size for your application plus any anticipated growth. If for instance you describe 10 Binary Inputs today and later increase the size to 20, you will have effectively changed the location of your Analog Inputs, Counter

Data, Binary Outputs and Analog Outputs by 10 locations.

If you choose not to do this then you should enter one or more commands for each data transfer. In this instance you could change the data AND change the

[BACKPLANE DATA EXCHANGE] commands to maintain your mapping in the

PLC.

Page 140 of 153 ProSoft Technology, Inc.

April 22, 2008