Reference
Analog Relay Mux Board
AD1200 Input Channel Select Jumpers.
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The AD1200 input channel select jumpers determine to
which channel on the PC A/D card the output of the relays is
routed. The A/D conversion are then performed with this channel
selected on the PC AD1200 card. Since the relays are switching
differential signals two jumpers are used to select A/D input
channel, the Channel and its return line. In differential mode
there are 8 possible input channels for the A/D converter.
Figure 1-5. AD1200 Input Channel Select.
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JUMPER
LABEL
ADC Channel Selected
______
_____
____________________
ÚÄÄ¿
³ÛÛ³
ADCH00
Channel 0
DEFAULT
³þþ³
ADCH01
Channel 1
³þþ³
ADCH02
Channel 2
³þþ³
ADCH03
Channel 3
³þþ³
ADCH04
Channel 4
³þþ³
ADCH05
Channel 5
³þþ³
ADCH06
Channel 6
³þþ³
ADCH07
Channel 7
ÀÄÄÙ
Relay Made Feedback Select Jumpers.
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The ADMUX board has break before make circuitry. There
is a time delay after outputting the address on the digital output
port before the previously made relay breaks and the newly the
selected relay makes and the analog input is switched through to
the AD1200 channel. To ensure that sufficient time elapses
before the A/D conversion is taken a relay made signal can be
fed back from the ADMUX board on to one of the bits of the
AD1200 digital input port. Software should poll this port waiting
for the correct bit to go LOW before the A/D conversion is
triggered. Only place one jumper on these pins.
The legend on the ADMUX board is incorrect in labelling the
line CH0, CH1 etc. They should be labelled DI0, DI1 for Digital
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