Batch reactor-Temparature tansmitter loading

Hi guys,
     Our batch reactor in process lab has duplex type RTD.It placed at bottom side of reactor.Here is the problem reagrding same RTD and Transmitter while checking its loop From DCS to field.
 Problem is:

•   Reactor temperature control module showing BAD device indication.It means either device is not connected or its not working

 While searching the root cause of problem we did following steps :

• Started with RTD checking.Measured resistance between 3 Terminal RTD and found it is ok at room temparature.
• Next we checked voltage comming from DCS to tansmitter.As it is duplex RTD we got 11.5 V and 13 V at both transmitter.so we decided to check the loop.
• Firstly in process lab upper junction box we checked cable continuity and we found it ok.Cable tag number 25/Ax AI/41 n so on...so from this we can esily found the same cable in DCS lab and for cross checking checked its continuity in JB.
• We found 24 V coming from DCS by rmoving cable from field instrument but when we were connecting same cable to transmteer voltage drop had occured so the module is showing device is not connected or failure as 24V loop is not completed.
• Now we are checking Transmitter ,so we can make conclusion why voltage drop occuring may be its because of transmitter load.

Just do the same steps when your checking loops in plant.These small things lead you good Instrumentation and control engineer.

take care........