Bronkhorst FlowDDE - Manual (Page 14)

BRONKHORST ®
4.5 T
EST COMMUNICATION
For maintenance and service operations, it is often required to read from or write to a certain parameter. FlowDDE
contains two test facilities: one to test FLOW-BUS and DDE communication and one to test lower level ProPar
communication.
4.5.1 Test FLOW-BUS and DDE
Open the FlowDDE test form from the menu FLOW-BUS >> Test FLOW-BUS and DDE or F6. The following window
appears.
The window consists of two sections. At the Test FLOW-BUS section parameters can be read and written directly to
the instrument, regardless of the DDE behaviour that a separate poll command is required to read a parameter value
and only changes are written to the instrument. The DDE value is updated on read, but not on write.
On the contrary, at the Test DDE section parameters can be read and written like any DDE client would do. Pressing
Read shows the current value at the DDE level, but the actual instrument value is not read and may be different. At
Write the value is written to the DDE level and, because of the nature of DDE, only if it is different than the previous
value, the value is written to the instrument.
At the Test DDE section links
to client applications, e.g.
Microsoft Excel, can be easily
made. Select the channel
and parameter to which a
link is to be made.
Press Copy link to copy the
link to the clipboard. In the
client application, use the
Paste Special option and
select Paste link to paste the
link (e.g. Paste Special in
Microsoft Excel, see image).
Any parameter value change
will be sent to the client
application.
The other way around is
possible as well. Copy a link
from any application (e.g.
copy a cell from Excel). In the test form, press Paste. Any change in the application’s field result in the parameter
value in FlowDDE to be updated. Note that when the communication is closed, all links will be terminated and will not
be restored when the communication is opened again.
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