Bronkhorst EL-FLOW Base 2014 - Manual (Page 15)

BRONKHORST HIGH-TECH
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
A special RS232 cable (7.03.366) can be ordered separately. It consists of a T-part with 1 male and 1
female sub-D 9 connector on one instrument-side and a normal female sub-D 9 connector on the side of
the computer. By means of this cable it is possible to offer RS232 communication and still be able to
connect power-supply and analog interface through the (analog) sub-D 9 connector.
3.4 Modbus RS485 operation
This chapter is limited to the description of the interface between the Modbus Mass Flow Controller
with a master device. It will explain how to install an EL-FLOW Base instrument to your Modbus system.
It only contains the information that is needed most.
The implementation of the Modbus interface is based on the following standards:
[1] MODBUS Application Protocol Specification V1.1b, December 28, 2006
[2] MODBUS over Serial Line specification and implementation guide V1.02
There is no mutual communication between Modbus slaves; only between master and slave.
More detailed information about Modbus can be found at http://www.modbus.org or any website of
the (local) Modbus organisation of your country (when available).
Base
FlowDDE
server
Application 1
Application 2
Application n
RS232
DDE-link
DDE-link
DDE-link
Windows based Personal Computer Instrument
9.17.061 EL-FLOW Base Series Mass Flow Controllers Page 15