get 3G signal strength - connected via 3G

Hi guys,
I trie to get or readout the 3G signal strength. But I am connectet via 3G.
Is there any possibility to solve my problem?

I tried:
[admin@MikroTik] > /interface ppp-client info 0
failure: can’t reuse channel while ppp-client running!

When I type:
[admin@MikroTik] > /interface ppp-client disable 0
[admin@MikroTik] > /interface ppp-client info 0
I get it:
signal-strengh: -69 dBm


Hardware:
RouterBoard 411U + Sierra MC8790 3G Card.



Greetings

Solved my problem on my own.
Data + Info Channel were Chan 4.
I moved Info Channel to Channel 3.

Now it works properly.