Checking signal strength

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This topic contains 4 replies, has 3 voices, and was last updated by  Lonny Knudson 3 years, 10 months ago.

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    Alex Warden


    is it possible to check Modem’s signal strength over http API or SNMP?
    I know there is a way with telnet and AT+CSQ, but telnet queries fail if you build up and close telnet sessions too frequently (+CME ERROR: 3 for AT+CSQ).

    We have several SF100-G devices (fw-Ver. 1.51.28) in use for alerting and we would like to check signal strength of each device before a SMS gets sent. Device with the best signal strength should then dispatch the sms.
    Since sometimes there are several SMS within 10 secs, telnet is not the best solution for live-status checking of the signal strength.
    (P.S. We use bash script and the iSMS-HTTP-Send-API for sending SMS.)


    Bryon Davis

    Hi Alex,
    Sorry, there isn’t an API or SNMP method to check the signal strength. And we don’t recommend using telnet directly to the modem since that takes complete control of the modem and locks out the iSMS firmware until the connection is disconnected. This can interrupt the iSMS sending and receiving and case lost messages.

    You may be able to pull the signal strength from web interface’s SMS Statistics menu.



    Alex Warden

    Hi Bryon,

    thanks for the reply.

    I wasn’t aware about the complete lock-up during telnet sessions, good to know. I guess one could pull the signal strength info with a little bit of perl scripting from the web interface…

    Maybe you guys could add this feature to API in the future fw version, to make it easier for everyone. I think it’s really needed, especially for alarming purposes.

    Recently one of our SF100-Gs devices had zero singnal strength for a few hours (provider problems) and we failed to notice it…
    Currently our SMS-script only checks network availability before redirecting SMS-Message to a first reachable/available SMS-modem (we have several SF100-G with different SMS service providers).
    So we need to check the signal strength as well, to increase the chances of SMS-delivery.


    Alex Warden

    Another somewhat related question:
    Is there some some addition hardware one could buy or any software tweaks for SF100-G, to enhance the antenna gain?

    • This reply was modified 3 years, 10 months ago by  Alex Warden.

    Lonny Knudson

    Hi Alex,
    There are no controls built into the cellular radio that would allow an end user to modify antenna/receiver/transmitter gain. For stationary devices low signal issues are typically addressed by adjusting antenna placement, trying high gain or directional antennas, boosters/repeaters, etc…

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