Bronkhorst FlowDDE - Manual (Page 18)

BRONKHORST ®
6 FLOWDDE TECHNICAL DETAILS
In the following diagram, the communication from a DDE client to the instrument is schematically drawn. The
FlowDDE application makes use of the Flowb32.dll and the parameter database.
A DDE client communicates to FlowDDE using DDE messages. FlowDDE uses the parameter database for parameter
information and the Flowb32.dll to perform the low level communication to the FLOW-BUS. The Flowb32.dll has
methods to easily send or request a parameter value to a certain node, process and parameter and to get the
answers. From the calls to these methods, it constructs the required FLOW-BUS messages in the binary ProPar
protocol, sends these messages and receives and interprets the answers from the instruments.
Included in the
FlowDDE installation
FlowDDE application
DDE client
Flowb32.dll
RS232/FLOW-BUS interface
or multibus instrument
FlowDDE
parameter database
DDE messages
ProPar (binary)
calls to DLL
Page 18 FlowDDE 9.17.067