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Gemalt EH6 Modem: Connection Failure Reason | Telit Cinterion IoT Developer Community

July 29, 2017 - 10:22pm, 2024 views

Dear Staff:

I am using a Gemalto EH6S modem in transparent PAD mode.

It isn't clear to me why the TCP connection establishment failure, described below
occurs. Any insight you have about the problem would be appreciated. Also, when
RF conditions are good, I am able to establish a TCP connection without problems.

The general problem is that after at least one connection failure, if you wait
about 2 minutes and attempt another connection, it fails with the following
diagnostic. All subsequent connection establishment attempts fail unless,
you turn the modem off and then on again.

    +CME ERROR: operation temporary not allowed.

The diagnostic after the first connection failure is something like this and
RF conditions are not too good.

    ^SIS: 2,0,94, "PDP: connection failed"

The sequence of AT commands issued to the modem--via the serial port, in
the connection establishment attempts are as follows and only AT^SISO fails.

    AT        // Make sure modem is alive
    AT^SIP        // Restore pre-programmed configuration.
    AT+CSQ        // Evaluate RF signal quality.
    AT^SISO        // Establish a TCP connection.

Best Regards,

Paul R.