so you have a clip that goes to the tool what is earth (common) and the signal wire going to the touch plate.
ground is the ground pin on port1 between pin 15-16 and signal wire is pin 15 on the C25 board
also what is the voltage between the clip and the plate if it is below 2.8vdc that might be the problem.
4v
Have you got a separate 5v power supply you could try
I do have a separate 5v power supply, you can see it in the attachment
the ESS should be on it's own 5vdc line with a common (earth) it the best way to do it, a lot of noise problems I was having went away after I rewired the whole machine to a common and it`s own 5vdc line for the ESS.
and moved the high and low common and power wires so there was no side by side wires, a cross over at one spot what is fine and the high and low common have there own star point side by side what is also fine.
The power supply I installed for the ESS is grounded to the chassis, common to the earth ground of the 220v from the house. What I'm unclear about is there are now 2 grounds, one from the C25 board and one to the chassis/earth from power in from the house. The power supply I installed has line, neutral, and ground, the ground on the ESS is derived from 5vdc- from the 5v power supply I installed, where s the common ground for the vdc? The chassis is grounded VAC, the ESS/C25 is VDC. I'm probably not understanding how the grounding works but hopefully some one can straighten me out.