BRONKHORST®
9.17.061
EL-FLOW
Base
Series Mass Flow Controllers
Page 17
3.4 Basic RS232 Flowbus operation
RS232 Flowbus communication can be used for operating your instrument using the Bronkhorst®
FLowDDE server application.
Physical layer and communication protocol are detected automatically upon reception of messages.
These messages must be sent using the correct combination of physical layer and communication
protocol. After every power-up the communication detection mode is active.
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 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
Base
FlowDDE
server
Application 1
Application 2
Application n
RS232
DDE-link
DDE-link
DDE-link
Windows based Personal Computer
Instrument
