In article , Brian Gregory [UK] wrote:
A sensor needs to be modified to work off a 24V DC supply and provide a
4-20mA output.

How is this normally done?

that depends on what the sensor needs to be modified from

Is it okay if the 4-20mA output has a common connection with the power
supply or should it be totally isolated. What is normally expected by
typical control equipment?

that depends...

Bye.
Jasen