Keithley 4200A-SCS - Pulse_Trig_Polarity

Section
13: LPT library function reference Model 4200A-SCS Parameter Analyzer
Reference Manual
13-154 4200A-901-01 Rev. C / February 2017
Example
pulse_trig_output(VPU1, 1)
Sets the pulse card trigger output on.
Also see
Pulse generator card output trigger (on page 5-68)
pulse_trig_polarity (on page 13-154)
pulse_trig_polarity
This command sets the polarity (positive or negative) of the pulse card output trigger.
Usage
int pulse_trig_polarity(int instr_id, long polarity);
instr_id
The instrument identification code of the pulse card, such as VPU1 or VPU2
polarity
Output trigger polarity:
• Negative, falling edge: 0
• Positive, rising edge: 1
• Default:
1
Pulse modes
Standard, Full Arb, Segment Arb
Details
Trigger output provides a TTL-level output that is at the same frequency (period) as the pulse card
output channels, but has a 50% duty cycle. It is used to synchronize pulse outputs with the operations
of an external instrument.
The external instrument that is connected to the pulse card external trigger may require a positive-
going (rising-edge) pulse or a negative-going (falling-edge) pulse for triggering.
If a polarity value other than 0 or 1 is sent, it will map to 0 or 1 in the following manner:
if(polarity <= 0)
pol = NEGATIVE;
else
pol = POSITIVE;
4220-PGU and 4225-PMU: Do not use the two external falling trigger sources
(pulse_trig_source function) with the positive trigger output polarity (pulse_trig_polarity
function) on the master card that triggers itself and other subordinate cards. These two falling trigger
sources should only be used when an external piece of equipment is used to supply the trigger
pulses to the 4220-PGU and 4225-PMU. This applies to all three pulse modes (standard pulse,
Segment Arb, and full arb).