Black Box GEH-6510 - Manual (Page 14)

10 •••• Chapter Two - Overview DDE Server User’s Guide
Networks
The network consists of an interface at the host PC and the cables connecting the
various devices to the host. There are physical requirements and limitations to the
networks, which are explained in GEH-6502, POWER LEADER Network
Architecture Guide.
PMCS DDE Server
The PMCS DDE Server has two basic functions: it collects data from attached
devices and it provides data to client applications (both on the host PC and on
networked PCs).
The PMCS DDE Server keeps track of the devices attached to the PMCS networks,
listens for requests for data from client applications, and, at specified intervals, polls
the requested data from the appropriate devices and reports it back to the clients. The
Server does not continuously poll all data from each device unless it is told to do so;
to do this would require enormous network bandwidth and result in degraded
performance. Instead, the PMCS DDE Server retrieves only the specific data that
client applications have requested.
Client Applications
Client applications request specific data from the PMCS DDE Server and then
provide calculations, trending, and display of the data on screen and/or printer.
Various client applications are available to serve different needs. Event Logger,
Waveform Capture, and Cost Allocation are just a few of the applications that are
fully optimized for PMCS.
Any DDE-compliant application can request data from the PMCS DDE Server by
initiating a “conversation” with the server and providing the correct information
phrased in DDE format – i.e., what data from which device.
A common example of a DDE-compliant application used to analyze data from the
PMCS DDE Server is Microsoft Excel, which provides data manipulation and
analysis tools. However, any DDE-compliant application may retrieve from the
PMCS DDE Server. For instance, a presentation on the power consumption at an
industrial facility might be created using Microsoft PowerPoint, charting power
consumption data requested from the PMCS DDE Server.
What’s Next
You’ve now learned about the four major parts of PMCS – next you’ll learn how to
configure your PMCS DDE Server.