Another common issue where 4-20 ma loops is concerned is the type of transmitter in use. If the loop is powered by the control system no isolation is required.
If the transmitter is 4-wire (field powered) then isolation is required to prevent tying the field power to the control system...
I do not understand "no access to the ENVOX administrator (envoxa) forms system". Is this a VMS system? If so "envoxa" issued at a VMS $ prompt should envoke the administration forms. Try selecting "administration" under the "More" menu on the upper...