4-20 ma output circuit correction

Job ID: 33273149

Budget: ₹600 – ₹1,500 INR

My instrument is giving 4-20 ma as signal output. Everything is working ok in normal condition. But if 2 instrument having common dc supply and common PLC to read 4-20. Then signal is deviating.
Attached is my circuit diagram for 4-20 ma signal.
Support is required to check and correct it.