BCI Capnocheck Plus - Page 25

Chapter 3: Capnocheck Plus Circuit Description
SIGNAL DESCRIPTION
vec VCC is the regulated +5 VDC supply generated by +5 volt power supply
regulator chip U20 and its discrete components.
VDD Same as VCC.
VSS Digital ground.
WDI Watch dog timer input signal, resets watch dog timer.
/XCS, /XRD, Signals generated by U4 to control display board.
/XWR, XAO -
Capnocheck Plus Service Manual 3-11