2-26
Functional Description
You can select only one interrupt at a time. If you are using an interrupt,
you must select the interrupt level (2, 3, 4, 5, 6, or 7) using a jumper on
the board. If you are not using an interrupt, you can disable interrupts
using a jumper on the board. Refer to page 3-14 for more information.
Note:
If you are acquiring data in the background, interrupts must be
enabled and the interrupt source must be an EOC interrupt.
If an interrupt condition is satisfied, an on-board flip-flop is set. If
interrupts are enabled (through both hardware and software), the board
generates an interrupt to the host, driving the selected host interrupt line
to an active state.
Power
The analog circuitry on the DAS-800 board is powered by the ±12 V of
the host computer. The DAS-801 and DAS-802 boards contain a DC/DC
converter to provide power to the analog circuitry.
Note:
Many laptop computers and other types of battery-operated
computers do not have a
−
12 V power supply. If your computer does not
have a
−
12 V power supply, you cannot use a DAS-800 board.
The host computer can provide power for EXP-16, EXP-16/A, and
EXP-GP expansion boards and MB Series backplanes; however, certain
power limitations exist. Table 2-3 lists the maximum number of
expansion boards and backplanes that the host can power.