I am using GE865-quad
i see that if connected device closes connection telit device sometimes can not detect socket is closed. may Stay like there is a connection 1-2 minutes. If i try to send data it finds out there is no connection.
i suspect there is a tcp setting about it but couldnt find out.
and another question i am using MDM.getDCD() as if there is socket connection. it is purpose of it, right? i know in rs232 it is used if there is a device connected but it seems i little blur here
Try to use the <keepalive> option in AT#SCFGEXT; indeed DCD should signal connection state, if is not deactivated with AT&C.
i set that value 240 thinking connection will keep alive for 240 minutes but i think it is sending keepalive packet interval
Set it to 1 for one minute max delay of closure announcement.
i need to rephrase to understand properly
if i set that to 1 then module will close socket after one minute idle time
240 for 4 hours
i had already set that to 240 to keep alive connection maximum alie time while i was having pproblem i first mentioned
One explanation, and another one. Has nothing to do with graceful closure, but with connection testing with "ACK" packets.
Thanks cosmin Sorry to bother you with this. i studied tcp connection before but i looked articles anyway
but my point is 240 minutes time may be the time that device keeps sending keepalive
or sends keep alive once a 240 minutes
but i assume that 240 minutes is 4 hours so it cant be keepalive package send interval so the device tries to keep connection alive for 4 hours
so my question at start comes as a problem again because my keep alive value is 240 but device doesnt get the conneciton is off immediately. (sometimes immediatel sometimes 1-2 minutes later). it is a problem when we want to make connection one after another.
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