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S M Unisens E problem

Started by oilyrag, October 18, 2015, 19:52:52 pm

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Hi. Is anyone using one of these lovely little sensors?

I have a small problem in setting mine up. In the alarm list there is a setting for 'Spannung'. I had assumed that this was for a minimum battery setting, but when setting it at 10.6v (I am using a 3 cell LiPo), the alarm goes off at 11.4v.

(In setting up I am using a part discharged battery and 11.4v is the actual voltage).

Interestingly if I set the alarm for anything above 11.4v it still goes off! In addition if I try to disable this particular alarm, it still goes off!

Can anyone advise please as I am running out of ideas......



Hi Pete, I use a couple of these with my Multiplex M Link system and haven't noticed what you've seen, what radio system are you using, a couple of things to check would be

1) An alarm setting on your transmitter isn't giving the alarm
2) The Unisens has a 2nd voltage alarm "startspannung" to prevent you from taking off with an already discharged battery, is it this alarm going off and not the main voltage alarm.


Hi Frank! Thanks for coming back to me as I am a bit perplexed.

I am using a Royal Evo Pro/SX9 and set up the voltage alarm on display 3 to avoid the M Link receiver telemetry on displays 1 and  2.  I'll try moving it to a higher display number to avoid any conflicts.

Also, I was using a part discharged LiPo when setting up. (11.4v) I'll try using a fully charged battery instead.

I have the 'Startspannung' set at 12.4v, so that could be the answer if the display title on the transmitter is truncated, i.e not 'Startspannung' but only 'Spannung' and both voltage alarms run on the same display.

Thanks for the pointer. I'll try all of the above and will post again later.


Pete, the Royal Pro/Sx automatically display the alarm, so when an alarm comes up it goes to that display, so if you have plugged in a partially discharged Lipo it will alarm on the "Start Voltage" setting and show that alarm condition. Providing you haven't set any telemetry readouts to the same address it doesn't matter which address/screen they are on.

I'm 99% certain it's the startspannung which is alarming as you've plugged in a partially charged battery. I'm not 100% sure, but I think if you put in a start value and don't set it to alarm it uses this value to reset the mah counter, so if you are flying an electric glider say and land for a coffee with the battery only partially discharged, you can launch again and the mah will continue from where you've left off, if you plug in a fully charged battery it will reset.


October 19, 2015, 11:44:14 am #4 Last Edit: October 19, 2015, 11:46:16 am by dickw
I can't help you with the Multiplex Tx alarms, but I can confirm that on my Jeti Tx the UniSens "Startspannung" alarm just comes up as a general "Low Voltage" warning if the model is turned on with a discharged battery connected.

I think Frank is probably right and that is what you are getting.

All my other alarms are set within the Tx and are more specific.

Grow old disgracefully


Frank, you are absolutely right!

I used a fully charged battery and guess what? No alarm and all the display addresses working perfectly. It appears that both 'Startspannung' and 'Spannung' show alarms through the same display.

It makes sense really as only one of the voltage alarms could be activated at any time, either high or low, but not both.

Many thanks for your help. I really appreciate it as yesterday I was tearing my hair out (what little of it there is left anyway)