Xycom XVME 590 Manual page 63

XVME-500/590 Manual
February, 1988
Procedure
1) Be sure proper jumper alignments are in place. Connect the external-
trigger source to pin 50 of connector JKl, and
trigger
2) Write a control byte to the status/control register (base + 81H) that sets
bits D5 and D6 to logic '1'.
Select the desired channel by writing the channel number to bits D0 thru
3)
D4 of the gain/channel register.
properly initialized (programmed) after power-up, it will not be necessary
to rewrite the gain at this time (unless a gain change is required).
4) The selected channel will initiate a conversion on the rising edge of the
external trigger.
registers.
edge of the external trigger, or until a new conversion is forced on the
channel via bit D7 of the status/control register.
Figure 3-6. External Trigger Pulse
source-return to pin 49 of connector JKI.
The conversion results are read from the A/D data
The next conversion will not take place until the next rising
100 nsec.
minimum
Assuming that the Gain RAM was
3-19
Rising edge
triggers
conversion
connect the external-