AD1200 Reference
Installation Guide
AD1200 card. Maximum permissible output current is
20 milliamps. The Maximum output current is largely
determined by the capacity of the power supply
installed in the PC. Check its rating.
Power ground is internally connected to analogue
ground, AGND.
iv)
Digital Lines.
Digital Output 0-7.
These are the 8 lines from the digital output port.
They are TTL compatible.
Digital Input 0-7.
These are the 8 lines to the digital input port. They
are TTL compatible.
Digital Ground.
The ground return for the digital input and digital
output lines. There are 7 digital grounds and any
external digital circuits connected to the digital input
or output lines should be earthed via these ground
lines.
The digital grounds are internally connected to
analogue ground, AGND.
v)
External Clock & Trigger.
External Clock.
The External Clock input can be used instead of the
onboard 600kHz oscillator to clock the A/D, DAC0
and DAC1 converters and to initiate IRQs and DMA
transfers to the converters and the digital port lines.
The clock is TTL compatible and the frequency can
be in the range DC to 1MHz.
External Trigger.
The negative going edge of the External Trigger
input can be used to start a series of conversions or
data transfers to the various ports. The trigger is TTL
compatible.
Page 48
Chapter 2
