IBM 7220 Car Amplifier User Manual


 
6-21
Chapter 6, COMPUTER OPERATION
BYTE [n] Digital output port control
The value of n, in the range 0 to 255, determines the bits to be output on the rear
panel digital output port. When n = 0, all outputs are low, and when n = 255, all are
high.
6.4.08 Auxiliary Inputs
ADC[.] n Read auxiliary analog to digital inputs
Reads the voltage appearing at the rear panel ADC1 (n = 1) and ADC2 (n = 2)
inputs.
In fixed point mode the response is an integer in the range -12000 to +12000,
corresponding to voltages from -12.000 V to +12.000 V.
In floating point mode it is in volts.
TADC [n] Auxiliary ADC trigger mode control
The value of n sets the trigger mode of the auxiliary ADC inputs according to the
following table:
n Trigger mode
0 Asynchronous (5 ms intervals)
1 External (rear panel TRIG input)
2 Burst mode, fixed rate, triggered by command (ADC1 only)
3 Burst mode, fixed rate, triggered by command (ADC1 and ADC2)
4 Burst mode, variable rate, triggered by command (ADC1 only)
5 Burst mode, variable rate, triggered by command (ADC1 and ADC2)
6 Burst mode, fixed rate, External trigger (rear panel TRIG input) (ADC1 only)
7 Burst mode, fixed rate, External trigger (rear panel TRIG input) (ADC1 and
ADC2)
8 Burst mode, variable rate, External trigger (rear panel TRIG input) (ADC1
only)
9 Burst mode, variable rate, External trigger (rear panel TRIG input) (ADC1
and ADC2)
In the burst modes, data is stored in the curve buffer. Use the LEN command to set
the number of points required. Note that it may be necessary to enter CBD 32 before
setting the length, if the curve buffer has previously been used for more than one data
type. The data is read out from the buffer using DC[.] 5 for ADC1 and DC[.] 6 for
ADC2. If the length is set to more than 16384 and a burst mode which stores both
ADC1 and ADC2 is specified then the curve length will automatically be reduced to
16384 points. Note also that setting the TADC parameter to any value other than 0 or
1 may affect the CBD parameter, as follows: