question about Endress Hauser PMP71 pressure gauge and 4-20mA output

[defcon.klaxon]

Hi all,


Well, here I find myself at a former client after I left water treatment trying to help him get the plant back up and running after a snow storm and severe electrical damage.



Long story short, the water tanks use Endress & Hauser PMP71 pressure gauges to infer level. We replaced a damaged one and on the local readout we do see level info, but no 4-20mA at the PLC. I moved the signal to an unused analog input in case the input we were using before was damaged, but no dice.


I was wondering if these level sensors are set up to provide 4-20mA signal directly from the factory, or if that has to be set up. Checking the E&H website, it's the classic situation of hundreds of documents but none seem to be helpful.


If anyone could help I would be greatly appreciative.



Thanks!

 

[danw]

PMP71 is a 2-wire, loop powered, 4-20mA transmitter. It needs a 24Vdc power supply in the loop to power it.


Connections are the left two screw terminals, (+) on the far left (connects to the 24Vdc (+)) and (-) in the middle that connects to the analog input (+) terminal. Polarity is important.



Those transmitters can have a keypad under the cover on the very top that can be used to configure the unit for the correct range, 0-15 feet or 0-4.5m or whatever. LRV (zero) URV (span) and engineering units must match what the old one was in order for the receiver with the analog input to interpret the 4-20mA signal correctly.

The alternative is to use a HART handheld communicator to configure the range and engineering units.

 

[defcon.klaxon]

Thanks danw!

I was able to get things sorted, and long story short the analog inputs to the PLC it was connected to were damaged. Swapping the PLC fixed things, and no modifications to the level sensor were needed.