Hello. AI2 input is different than inputs AI1 or AI3.
AI2 is bipolar input, it means that voltage between AI2+ and AI2- can variate from 10V to -10V.
Such input is sometimes called differential input.
Possibilities to connect potentiometer to AI2 are following:
1. Using external 10V supply and with AI2 configured as unipolar (AI2t=10v) [AI2 type = 0-10VDC]. Then connect 10v from ext supply to beginning of potentiometer. 0V from ext supply to the end of potentiometer and also to COM on ATV340 (analog I/O COM). AI2- connect also to the same COM. Third potentiometer outlet (variable) to be connected to AI2+
2. Using internal 10V supply and with AI2 configured as unipolar (AI2t=10v) [AI2 type = 0-10VDC]. Then connect connect 10v terminal from ATV to the beginning of potentiometer. COM to the end of potentiometer. AI2- connect also to the same COM. Third potentiometer outlet (variable) to be connected to AI2+.
3. Using external 20V supply and AI2 configured as bipolar (AI2t=n10v) [AI2 type = -10/+10VDC]. Here you will have to create artificial zero point from 20V to have +10..0..-10V using e.g. by two same resistor in series between ext 20V and ext 0V. The resistors should have resistance at least 10x lower than ATV340 AI2 input resistance. 1kOhms resistors are OK. The middle point (artificial zero), will be connected to AI2-. The variable potentiometer outlet will be connected to AI2+. Beginning and end of potentiometer will be connected to ext 20V and ex 0V. Do not connect ext 20V and ext 0V anywhere else in ATV340. Especially take care ext 0V not to be connected with ATV340 COM
AI2 is bipolar input, it means that voltage between AI2+ and AI2- can variate from 10V to -10V.
Such input is sometimes called differential input.
Possibilities to connect potentiometer to AI2 are following:
1. Using external 10V supply and with AI2 configured as unipolar (AI2t=10v) [AI2 type = 0-10VDC]. Then connect 10v from ext supply to beginning of potentiometer. 0V from ext supply to the end of potentiometer and also to COM on ATV340 (analog I/O COM). AI2- connect also to the same COM. Third potentiometer outlet (variable) to be connected to AI2+
2. Using internal 10V supply and with AI2 configured as unipolar (AI2t=10v) [AI2 type = 0-10VDC]. Then connect connect 10v terminal from ATV to the beginning of potentiometer. COM to the end of potentiometer. AI2- connect also to the same COM. Third potentiometer outlet (variable) to be connected to AI2+.
3. Using external 20V supply and AI2 configured as bipolar (AI2t=n10v) [AI2 type = -10/+10VDC]. Here you will have to create artificial zero point from 20V to have +10..0..-10V using e.g. by two same resistor in series between ext 20V and ext 0V. The resistors should have resistance at least 10x lower than ATV340 AI2 input resistance. 1kOhms resistors are OK. The middle point (artificial zero), will be connected to AI2-. The variable potentiometer outlet will be connected to AI2+. Beginning and end of potentiometer will be connected to ext 20V and ex 0V. Do not connect ext 20V and ext 0V anywhere else in ATV340. Especially take care ext 0V not to be connected with ATV340 COM
Released for:Schneider Electric South Africa
