single image by one hardware trigger

[Wee-Bey]

I think this voltage issue is the source of the problem. Notice in the documentation for your camera that the voltage range for a logical '1' is between 5V and 24V. Even if you are near the high end of this range, it might not function. When you say using a resistor didn't work, what do you mean? Were you able to confirm that the PLC signal was down to around 5 volts? Or when you say it didn't work, do you mean that you couldn't siphon off the voltage?

[Frank_Noe]

i noticed the difference between terminal block and PLC is the voltage value then i used a resistor to lower down the output voltage of the plc and it was around 5 volts but didnt work as i mentioned. and for being sure that i siphone off the voltage i used an interface relay between camera and plc with two open contacts for positive and minus as shown 

[Wee-Bey]

Then it might be the width of the signal. You say the PLC width is controllable. What about the width of the terminal block? What widths are you using? If the signals are identical, then we can identify the issue as something else.

[Frank_Noe]

The width of pulse out of terminal block is controllable also and i used to make it 10 ms. the plc output i can make its width as terminal block. i believe the solution is how to stop the camera from acquiring and wait for the next pulse from PLC but i`m not sure how to do it