2 wire analog sensor power supply issues

An analog Transmitter (Sensor) with 2 wire and 4 to 20 mA output, is connected to an analog input module. The sensor requires an external 24 vdc power supply.
If any interference or fluctuation happens on the 24 vdc power supply, it will probably affect the analog input readings.
Has anyone encountered this issue before?

http://www.plctalk.net/qanda/showthread.php?t=25914

https://support.industry.siemens.co...-a-compact-cpu-or-a-c7-device-?dti=0&lc=en-QA

The 4-20ma sensor will act just a "Voltage Regular" as long as the voltage is between it's recommended value the output will remain constant.

Example: If you are using a 24 vdc external power supply to power the sensor and it is measuring an output of 10.5ma that value will not change as long as you stay within the recommended supply.

Just like a "Voltage Regulator" if you are using a 5 vdc regulator the input can be between probable 6vdc and 24vdc but the output will be regulated to 5 vdc!

I'm trying to recall if I ever traced a noise issue to a DC power supply, and I can't recall one, and my experience goes back to older linear power supplies and the newer switch-mode power supplies (SMPS). I've used really cheap wall wart SMPS for short duration tests and setups and haven't seen a problem. Permanent panel jobs are all industrial 24Vdc supplies nowadays that have (remarkably) limited ripple.

A far more common cause of noise in 4-20mA circuits is VFD generated noise
http://www.eng-tips.com/viewthread.cfm?qid=419481

Here's a link to a discussion about the shield-connection-to-ground causing noise on a 4-20mA loop
http://www.plctalk.net/qanda/showthread.php?t=88718

Noise from a DC power supply can cause a problem with HART communications that runs on the 4-20mA current loop. HART spec includes spec of maximum ripple 0.2V p-p, Maximum noise at 500Hz to 10KHz of 1.2mV rms and a maximum series impedance of 10 ohms for the same frequency range as the max noise.

Good white paper on 4-20mA noise from Precision Digital:
https://www.predig.com/whitepaper/reducing-signal-noise-practice

Are you floating the DC supply?
Try grounding the DC-.

Don't share the 24VDC with logic bit.

No there will be no effect on the signal, however as it can be also used for the reference inside the PLC it could be a problem inside the PLC.