Hardware Reference
In-Depth Information
simply necessary to first read the data from (base address), bit-wise
or
the data
with the bit to be set, and then write it back to (base address). Using the example
addresses quoted earlier, the following single line of DOS BASIC will operate
the relay connected to OP1 without altering the state of any of the other relays:
OUT &H300, INP(&H300) OR 2
Further information concerning programming this type of interface appears in
Chapter 12.
Blue chip technology AIP-24
The Blue chip technology AIP-24 analogue input card provides 24 channels
of single-ended or 12 channels of differential analogue input. The board is a
120 mm short format PC/AT compatible card and its simplified block schematic
is shown in Figure 2.27.
The AIP-24 uses a 12-bit analogue-to-digital converter which provides a
resolution of 0.025%. A sample and hold amplifier is used to capture fast
moving analogue signals and freeze them in order to improve overall accuracy.
The successive approximation ADC can operate in unipolar or bipolar modes
Figure 2.27
Simplified block schematic of the AIP-24
