Ocean Optics PC2000-PC_104 - Manual (Page 14)

PC2000-PC/104 Data Sheet
outport_byte(port,cmd) set command to PC2000-PC104
cmd = cmd | 0x41 enable interrupts and triggers
if external software triggering then
while inport_byte(baseadd + 5) & 8)
== 0 wait on this line if you are external triggering, constantly query the
digital input on pin 26 of the 26 pin connector to check
for it to go high (+5VDC)
CheckTriggerMode() check the external trigger mode
if not scanning a dark spectrum or
using external triggering then
cmd = cmd | 2 if you are scanning a dark spectrum or using an external
trigger mode do not turn on the flash
outport_byte(port,cmd) set command to PC2000-PC104
This function does a lot. First, it identifies the PC2000-PC104 control port as baseadd + 4. It then
clears the MUX address of the A/D, sets the MUX address of the A/D, turns off the flash-during-scan,
resets the FIFO buffer, cancels the FIFO reset, enables the triggers and interrupt (this is VERY
IMPORTANT, as it is what makes it all work), and waits for an external software trigger on pin 8
of the DSUB15 connector, if requested. The function then triggers a scan.
Step 5: Service the Interrupt
When a scan is completed, your program is notified by an interrupt. You MUST service this interrupt
IMMEDIATELY. The interrupt service routine (ISR) must be as short as possible. Do as little
processing as possible in the ISR. The following is our ISR.
cmd = cmd & 0xbe turn interrupts and triggers off
CheckTriggerMode() check the external trigger mode
outport_byte(baseadd + 4,cmd) stop the acquisition
enable() restart interrupts
for i = 0 to 2047
indata(i) = (inport_word(baseadd + 6)
^ 0x0800) & 0x0fff
next i read 2048 data points from the FIFO buffer, convert to
unsigned values and mask off upper 4 bits (0-4095
value)
cmd = cmd & 0xbe turn interrupts and triggers off
cmd = cmd | 0x20 reset the A/D cards FIFO
CheckTriggerMode() check the external trigger mode
outport_byte(baseadd + 4,cmd) issue the command
cmd = cmd & 0xdf cancel the reset
CheckTriggerMode() check the external trigger mode
outport_byte(baseadd + 4,cmd) issue the command
outport_byte(0x20,0x20) send a non-specific EOI (end of interrupt) to the 8259
interrupt controller chip
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