9600 Service Manual - gmecorp-usa.com

6 C-Arm Control
CONTROL PANEL PROCESSOR PCB
OVERVIEW
S/N 69-0001 thru 69-2000 - Assy. #00-875603 - Sch. #00-875601
S/N 62-0001/69-2001 and higher - Assy. #00-878488 - Sch. #00-878486
There are 2 versions of this circuit board (see Figures 6 and 7). The functionality
of the two boards is the same. The circuitry on the earlier version (Assy. #00-
875603, see Figure 6) was divided to form two new circuit boards; the new
Control Panel Processor PCB (assy. #00-878488, see Figure7) and the Control
Panel Processor I/O PCB (see Figure 8).
The circuitry on the new Control Panel Processor PCB consists of the active
circuitry that required EMI/RFI shielding. The circuitry on the Control Panel
Processor I/O PCB consists of cabling connectors and passive components that
did not need shielding.
The theory of operation that follows applies to both Control Panel Processor
PCBs, however, component designators are different. Designators between
brackets, [ ] refer to the newer boards.
MICROPROCESSOR SECTION
U5 [U11] is an 80C196KC microcontroller running at 10 MHz Y1 is a10 MHz
crystal oscillator. DS1 indicates that EPROM code is being executed blinking at
two different rates: 200ms if waiting for communcations to be established, and
530ms after communications have been established.
U14 [U3] and associated circuitry create an external watch-dog circuit that must
see a falling edge every 150 ms or less. If the falling edge is not detected at pin 7
it will time out and generate a reset to both the micro-controller and PAL U7 [U8].
The Reset* signal goes low for 250 ms to generate a reset. U14 [U3] also
monitors the power supply voltage. It will hold the RESET output pin low
whenever VCC is below 4.62 volts (typically). A reset can also be generated by
MRESET* at pin 1 of U14 [U3] from the Technique Processor.
LS1 [on Control Panel I/O PCB] is a tone generator driven by U5 [U11] through
Q1 to indicate when X-rays are being produced and to indicate oyher key
closures.
E4 - configuration jumpers, currently not used.