ganutenator
Lifetime Supporting Member
do you always connect the 4 wire one to 24 negative, or do i have to call each time and be berated?
I understand, I was saying in the case of this transmitter it has 4 wire, but the 4th wire is not a ground/return but a discrete output. In fact if he grounded that wire and it is a pnp version transmitter, then it would short.
do you always connect the 4 wire one to 24 negative, or do i have to call each time and be berated?
If you are powering up the instrument, then you have to provide a return wire from the power supply.
return wire, duh.
i'm just confused on the feed wire sometimes being positive and sometimes being negative and not knowing how to know when w/o sounding like an idiot.
For a 2-wire sensor, it depends more on the input card than the sensor, I would say. Basically, you just need to have them in series, the proper ends connected to each other.ok, let me get more clear.
i got a sensor in my left hand a sensor in my right hand. once needs to be connected to 24 neg and one needs to be connected to 24 positive. pretend i'm an idiot. how do i tell?
+24v-----Sensor-----Input-----0V
+24v-----Input-----Sensor-----0V
1. In answer to the question above, a true 4 wire device requires a one wire to connect directly to the 24Vdc power supply (-)/return. That connection provides power to the device. But I doubt the Banner is a true 4 wire device.do you always connect the 4 wire one to 24 negative, or do i have to call each time and be berated?
3 and 4 wire sensors, you would need to look at a wiring diagram supplied with the sensor to know what it is expecting. Those are usually more picky about what wire goes where AND how the input card should be wired.
If the transmitter is not a loop powered device, then it's analog output will connect in parallel to the analog input.
If the transmitter is a loop powered device, then it will connect in series with the external power supply (even if this power supply is built in to the analog input module) and the analog input.
Attempting to explain this to someone who doesn't grasp the difference between a series circuit and a parallel circuit is an exercise in futility, I suppose.