Some questions about the 2601B trigger

Hello ! I have a 2601B, I want to use the pulse generator to generate a trigger signal, 2601B receives the trigger signal through the digital I / O interface, and then generates a pulse output in smua. Now the running program 2601B can not output the specified voltage. I don 't know if this is a code problem or a connection problem. Attachment is code. I have some questions to understand : 1.Use digio to receive the trigger signal, how the bnc line should be connected to the digio; 2.Using a pulse generator to generate a trigger signal, how to set the signal strength, time, type ( adjustable or TTL / CMOS ), active high or low; 3, Does Digio need impedance when receiving the trigger signal, if necessary, what are the requirements.

When you say the SMU is not generating the specified voltage, do you mean the instrument is triggering properly but the output isn't what you expect? Or do you mean the SMU is not triggering at all?

First, I recommend using digio.TRIG_RISINGA (A for acceptor) for digio.trigger[1].mode instead of digio.TRIG_RISING. This sets DIO line 1 to TTL Low and waits for the rising edge of a TTL pulse.

1. Your code sets the SMU to trigger on DIO line 1. See page 4-38 of the Reference Manual (https://www.tek.com/en/manual/source-measure-units/model-2601bpulse-system-sourcemeter-instrument-reference-manual2601b-pulse-system-sourcemeter-10-sec) for a diagram of the DIO port. If you're using bnc from pulse generator, you want the outer shell connects to ground (pins 15-21) and the center connector connected to pin 1.

2. The digio.TRIG_RISINGA mode will look for the rising edge of a TTL High pulse. The pulse width is not relevant based on your code.

3. See page 4-40 of the Reference Manual for the hardware schematic of the DIO pins. They all have a 100 Ohm resistor on them. If you are using TTL pulses you shouldn't need to worry about impedance.