GSev

Hi Fausto, Yes, I forgot to do the "floating" voltage source connection. If only I had read the manual before coming here! Thanks, -Greg

Hi Fausto, Keithley 2200-60-2. Set to 24V with about 250 mA to handle the solenoid demand. Attached is diagram. Orange channel has a 390 ohm resistor (measured at 388.2). Blue has 220 ohm resistor (measure at 221). I'm not particularly concerned with inaccuracy of the conversion just changes in shape and those drops. As I have three channels connected. Should I connect 1's CH#L to 2's AGND and 2's CH#L to 3's AGND? I think there is no other equipment connected to that fuse. It runs in a conduit that does have plenty of other wires. I'll run the tests.

Hi Fausto, Yes you are correct it should be using differential analog input. I'm using our internal sensors which I do not want to post information on a public forum. Resolution of orange line is 12 bit with a full scale of 200 psi. It has some input protections. Blue line is Prosense EPS25-1450 psiprosenseeps1001dps.pdf. Sense resistors are just some 0.5% through hole resistors that were selected based on the output. What are you looking for specifically? The blue line sensor has a PNP switch that commands a solenoid which either vents or pressurizes the manifold. The grey line indicates the change of state of the solenoid. The solenoid circuit has a flyback diode and a voltage divider to allow the DAQ to measure (grey vertical line). Sensors are parallel and connected to negative of the power supply. Solenoid negative is on the same line. Solenoid ground is connected to power bar. Laptop uses an external power supply that is connected to the same power bar. Thanks, -Greg Series2200_0.pdf

Hello, I ran some tests measuring two current output sensors (a 2-wire and 3-wire) using sense resistors using differential analog output and DaqAmi. Both connected on the same power supply, Keithley 2200. The blue and orange lines represent two pressure sensors with an input of shop air supply. As the drops are so fast I do not believe that it is the input and must be the measurement. Does anyone know the cause of this and how to avoid? Thanks!