Ehsan-ul haq
Member
Hi All,
I am working on a small PLC system having Compact Logix LE33 PLC having only two IF4 card. Some of these channels are used for 4 - 20 mAmps pressure transmitters and some vibration Tx. When system is operational these channels read the process variables correctly but as soon as system stops or pressure goes to zero, they start showing 3980 to 4001 value and under range bit becomes high in card diagnostics. All transmitters are 4 - 20 mAmps. There is only one source of 24 VDC. I have checked wiring which is as per manual and all commons are looped together.
I believe one common factor is effecting all these readings, cant figure out what. Any help would be appreciated. Thanks
I am working on a small PLC system having Compact Logix LE33 PLC having only two IF4 card. Some of these channels are used for 4 - 20 mAmps pressure transmitters and some vibration Tx. When system is operational these channels read the process variables correctly but as soon as system stops or pressure goes to zero, they start showing 3980 to 4001 value and under range bit becomes high in card diagnostics. All transmitters are 4 - 20 mAmps. There is only one source of 24 VDC. I have checked wiring which is as per manual and all commons are looped together.
I believe one common factor is effecting all these readings, cant figure out what. Any help would be appreciated. Thanks