Bronkhorst
®
9.17.057
page 19
- 8 selectable fluids (calibration settings for high accuracy)
- direct reading at readout/control module or host computer
- testing and self diagnosis
- response alarm (|setpoint-measure| too high for too long time)
- several control/setpoint modes (e.g. purge/close valve)
- master/slave modes for ratio control (FLOW-BUS only)
- identification (serialnumber, modelnumber, device type, user tag)
- adjustable minimal and maximal alarm limits
- (batch) counter
- adjustable response time for controller when opening from zero
- adjustable response time for normal control
- adjustable response time for stable control (|setpoint-measure| < 2%)
See 9.17.023 “Operation Instructions Digital Instruments” for more details about the parameters and
properties of ‘multibus’ instruments.
RS232 FLOW-BUS 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/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
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.
RS232 communication is only possible with a baudrate of 38.4 KBaud and can be used for either:
•
Uploading new firmware by means of a special program (for trained BHT-service personnel only)