I’m looking for information if VMB4AN provides power supply to the 4…20mA loop or it needs a separate power supply. Both solutions are used in the 4…20mA world. I’m designing an industrial grade pool temperature monitoring and AMB4AN will be my gate to the velbus system. The data sheet shows “power supply output for sensors: 24 VDC / 150 mA” but I can’t find info if this is a separate power output for sensors? Or maximum total current for 4 4…20 mA circuits? Obviously the maximum current in the 4…20mA loop is 20 mA, but voltage can be ~12 to ~30 V. I’m planning to use the VMB4AN with LKM213
And what do you think the answer is 
As if Velbus would miss something like that. 
Look at the top right hard side of the connections
VMB4AN
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Yes, VMB4AN has a 24V 200mA power supply for 4-20mA devices
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Thank you!! So it has all the bells and whistles! 
As always
Now, something that is a bit outside of pure velbus, but I hope someone here would know the answer. In what from the 4…20 mA will be available in velbuslink or openHAB? I will have one 0 to 100 deg C temperature sensor (2 wire) and an ultrasonic proximity sensor 30-250 mm (2 wire as well( to detect fluid level. I’d be OK with raw 4…20 mA values or a percentage.
I’m trying to understand how the whole system will work - it’s will be rather expensive, so I want to be sure it works before I start buying the parts 
For the temperature sensor you can use a PT1000 sensor (2wire) and load the datafile in Velbuslink.
For the fluid level (water) a common 4-20mA can be used like a FTVogue level sensor and load a 4-20mA datafile in Velbuslin like a “Catec … Lux 4-20mA.vsc” customizing it for in cm and thank height
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Would you like to remotely connect to one and explore it?
I have one on a demo unit, with a CT coil and a 2K thermistor.
I can add a 4~20ma water depth gauge, but the way the sensor data is translated and presented is the same.
(The rig is in the office now, but going to Derby College on Tuesday morning for a few days. After that, I’ll all be back in the office for 3 or 4 weeks)
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Thank you very much!!! I’m really impressed! From what I see I can do curves, so “a base level minus the actual measurement = real level” (*) should work. This is much more than I could expect - it’s really like an industry grade system. I assume the calibration data is something like a csv file?
Stuart - thank you for the offer! Let me know when you’re back, no need for the additional sensor. I just need to look around in the VelbusLink. Unless I can make a design with no actual devices…
With that flexibility I think I’ll find use for more than just one VMB4AN unit. 
(*) the sensor will be over water surface, so bigger distance mean lower level
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I’ll get it all powered up again this morning and send you the connection details 
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Thank you! I finished exploring, time for shopping. 
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