Bronkhorst LIQUI-FLOW mini (till 01-07-2013) - Manual (Page 13)

9.17.065 page 13
Dynamic Data Exchange (DDE) provides the user a basic level of inter process communication between Windows
applications. FlowDDE is a DDE server application. Together with a client-application, either self-made or with a
SCADA-program from 3rd-parties, it is possible to create an easy way of data exchange between the flow controller
and a Windows application. For example, a cell in Microsoft Excel could be linked to the measured value of the flow
controller and when the measured value changes, it will be automatically updated in the Excel spreadsheet.
Examples of DDE client applications: FlowPlot, FlowView, MS-Office, LabView, Intouch, Wizcon.
The FlowDDE server also offers a lot of test facilities and user adjustable settings for efficient communication with the
connected flow/pressure meter or controller.
How to setup a DDE link with FlowDDE is described in the help-file of the FlowDDE application.
Programming examples are available for making applications in: Visual Basic, LabView and Excel.
FlowDDE parameter numbers:
Reading/changing parameter values via FlowDDE offers the user a different interface to the instrument.
Besides the application name: ‘FlowDDE’ there is only need of:
• topic, used for channel number: ‘C(X)’
•
item, used for parameter number: ‘P(Y)’
A DDE-parameter number is a unique number in a special FlowDDE instruments/parameter database and not the
same as the parameter number from the process on an instrument.
Node-address and process number will be translated by FlowDDE to a channel number.
FlowDDE and other Bronkhorst applications are available at the Bronkhorst download site:
http://www.bronkhorst.com/en/downloads
For more information regarding communication through an RS232 interface, see document nr.
9.17.027: RS232 interface with FLOW-BUS for digital instruments.
3.5 Basic parameters and properties
3.5.1 Introduction
Every instrument parameter has its own properties. These properties are given in a table as shown:
Type Access Range FlowDDE FLOW-BUS
[type] RW  [x]…[y] [FB] [proc]/[par]
Type
Unsigned char 1 byte character
Unsigned char[x] x byte array (string)
Unsigned int 2 byte unsigned integer
Float 4 byte floating point
Access
R The parameter is read-only
RW The parameter can be read and write
RW The parameter can only be written when the Init Reset parameter is set to 64. See section
4.1.1 for more details.
Range
Some parameters only accept values within a certain range:
[x]
Minimal value of the range.
[y] Maximal value of the range.