Hi Guys,
I have field RTD's which are 4-wire. It has two red wires and two white wires. The input to my RTD compactlogix module (1769-IR6) is a three wire connection.
Currently, all my RTD values are coming in as full scale (32767). The sensor is a Pt385 100 Ohm sensor. When i measured the resistance across the two legs i got 112 Ohms.
For this type of sensor does it mean that at zero degrees it will read 100ohms? Also, could it be the wiring is messed up? Do i jumper the two whites together?
I am missing something quite fundamental here. If the ohms going into the PLC card is only 112ohms why would it interpret it as full scale?
I have field RTD's which are 4-wire. It has two red wires and two white wires. The input to my RTD compactlogix module (1769-IR6) is a three wire connection.
Currently, all my RTD values are coming in as full scale (32767). The sensor is a Pt385 100 Ohm sensor. When i measured the resistance across the two legs i got 112 Ohms.
For this type of sensor does it mean that at zero degrees it will read 100ohms? Also, could it be the wiring is messed up? Do i jumper the two whites together?
I am missing something quite fundamental here. If the ohms going into the PLC card is only 112ohms why would it interpret it as full scale?