2-18 250cx Series Maternal/Fetal Monitor Revision C
2036947-001
Equipment Overview: Theory of Operation
Theory of Operation
Systems Overview
The 250cx Series system is made up of front-end and back-end PWAs, system
power supply, and recorder module. The main PWA forms the heart of the monitor
control functions. This PWA along with the Communications PWA form the back
end of the monitor. The DSP/Display PWA is the bridge between the front-end and
back end sections. The front-end PWAs are housed in the sealed front-end card cage
and consist of isolated and un-isolated PWAs. The recorder assembly houses the
recorder PWA.
The basic block diagram below shows all of the PWAs and external parts as well as
their internal block functions. The block diagram description on the following page
attempts to show all of the PWAs and parts, how they are connected (cable or direct
plug-in), the areas of isolation (PWAs and cables), and a brief theory of operation for
a quick total system overview.