Using Loop Power with a PLC

I used to work at a plant that had all honeywell DCS systems and used loop power on 90% of their transmitters. The plant close for lack of business and now I have found myself in a plant using mostly PLC 5's. I have been ask to install 3 loop powered level transmitters but I'm not sure if it can be done using a PLC. On the DCS system the module sent out 0 to 24 volts DC to the transmitter. Based on the resistance of the measuring device it would drop the 24 volts to somewhere between 0 to 24 volts or 4 to 20 milliamps. You would then scale that value. How would I use loop power 2 wire control using the PLC 5. Do I need a special module that would sent out the loop power on one pair and then read back from that module and input value??? The particular device that I am installing is a 5303HA1S1V5AE0200RBE5M1 = $2937.60 from the website Website: http://www.emersonprocess.com/rosemount/products/level/m5300b.html
I would appreciate any help that you guys could give me!!

Thanks
Tommy

Loop powered instruments are quite common on the PLC-5. The difference is that on a DCS you typically just wire it up to the termination assembly, on a PLC you have to include the power supply in your loop. If you get the AB manual for the I/O module you are using, they have typical wiring diagrams. Another difference is that DCS systems usually have isolated channels, in the PLC-5 you can have differential (isolated) or single ended (all the transmitters share a common). Again, this is covered in the I/O module wiring diagrams.

Post your I/O module and we can help. Also scaling in a PLC-5 is much different than what's done in a DCS, there are no AIN blocks or such. You will most likely use the Compute instruction, within a ladder.

The DC power supply that you use for you transmitter should not be the rack mounted power supply that powers the PLC-5 rack.

Transmitter power is supplied from an independent power supply, typically 24Vdc.

Good advice from Ken Moore & Danw. Don't forget to add some circuit protection, e.g. 1/4 Amp fuse or breaker for each loop with a 1 Amp supply. Don't oversize the protection, a half amp fuse might never blow with a 1 amp supply, just pull the Voltage down.
Roy