connected to ground. This is done to protect the circuitry from
static discharges which can be of extremely high voltage.
NOTE: The terminal labeled "X" is the -6VDC supply. It is there
for compatibility with the Model 17A only. Normally, no
connection should be made to the "X" terminal.
FIGURE 2. TYPICAL INPUT CONNECTIONS
When all connections have been made, check that the cable to
the A/D card is plugged in. Also check that the Model 17B is
plugged in and that the computer is on. After checking for
function, provide strain-relief for all connections.
SECTION 2. OPERATION
Channel selection is accomplished by entering the A/D
channel selection code plus the number of the desired multiplexer
channel as the control code. For example, with the multiplexer at
A/D channel CH, if you are using a Model 134 or 140, the
instruction to select multiplexer channel MUXCHAN would be:
OUT ADC, 16 * CH + MUXCHAN
For a Model 141, the corresponding instruction would be:
OUT ADC, 128 + 16 * CH + MUXCHAN
Refer to your A/D card manual for more information on
channel selection.
The following BASIC program will scan 16 channels of data
and display readings in millivolts. Set CH equal to the actual
A/D channel number in line 2040. Set BOARDCODE in line 2030 to 0
if you have a Model 134 or Model 140; set it to 128 if you have a
Model 141.
1000 REM Sample program
1010 GOSUB 2000
1020 FOR MUXCHAN = 0 TO 15
1050 OUT ADC, BOA 16 * CH + MUXCHAN
1060 GOSUB 4000