How to generate one adjustable single pulse ?

Giles,

Should it be adjustable by a potentiometer or by an input voltage?
What is the signal level / VCC level?
Trigger and output polarity would also be helpful.

Thank you for your answer,

I didn't give all details, i'm sorry.  I would like to configure the pulse width with labview via a USB to I2C module.  With this USB-I2C module , i would like to generate a trigger and configure my pulse width.

I vision to use:

• First solution : an expander I/O for the the trigger and a timer with a capacitor,and I2C digital resistor to settle the pulse width ;
• Second solutio: a clock signal, a counter,a comparator, a register to configure the pulse width( with a rs bascule, i would like to generate my trigger which were on the "and logic gate" input1 ,and the clock on "and logic gate" input2. The and logic output is connected on a counter, and the comparator compare if A(register value)=B(rising edge), to send a "0"logic on the R-S Bascule reset;

Gilles,

I transferred your post to the logic forum. I believe this will result a helpful response.