I am new in automation industry and nowadays, I focus on learning analog input wiring with detailed since last time I damaged input module because of wrong wiring.
Here I have several questions about analog input wiring. They seems pointless to you but I need these answers to fully understand analog input concept. I would be appreciated if you answer these questions.
1- When using 2 or 3 wire 4-20ma current transmitter. Does analog output wire(4-20ma) always produce current with referenced to power supply common ? (I mean we can think this transmitter as a fixed voltage source and a variable resistor so the minus side of the voltage source is always linked to power supply common ?)
2- When using 2 wire 0-10v voltage transmitter, if the input module and transmitter is fed by same power supply. just wiring + side of transmitter to module will be enough (by wiring " - " of module and " - " of transmitter to common) ? I'd like to learn if the voltage produced by transmitter is always referenced to ground or can be any floating value.
3- The second question is valid for 4-20ma 4 wire transmitter. if both input module and transmitter is fed by same power supply. just wiring + side of transmitter to module will be enough (by wiring " - " of module and " - " of transmitter to common) ? It seems to me 4 wire transmitter output can be any floating value but what happens if we use same power supply for module and transmitter ?
Here I have several questions about analog input wiring. They seems pointless to you but I need these answers to fully understand analog input concept. I would be appreciated if you answer these questions.
1- When using 2 or 3 wire 4-20ma current transmitter. Does analog output wire(4-20ma) always produce current with referenced to power supply common ? (I mean we can think this transmitter as a fixed voltage source and a variable resistor so the minus side of the voltage source is always linked to power supply common ?)
2- When using 2 wire 0-10v voltage transmitter, if the input module and transmitter is fed by same power supply. just wiring + side of transmitter to module will be enough (by wiring " - " of module and " - " of transmitter to common) ? I'd like to learn if the voltage produced by transmitter is always referenced to ground or can be any floating value.
3- The second question is valid for 4-20ma 4 wire transmitter. if both input module and transmitter is fed by same power supply. just wiring + side of transmitter to module will be enough (by wiring " - " of module and " - " of transmitter to common) ? It seems to me 4 wire transmitter output can be any floating value but what happens if we use same power supply for module and transmitter ?