we developed a
modem using the GE864
Quad Automotive. On the modem a linux system runs. This system communicates via serial port with
the telit module. It establishes a ppp-connection. Using this module we have no
problems using the GPRS connection.
Then we changed the telit module to GE864 Quad Automotive V2. We did not
change the software and so the hardware (apart from the module). At first sight we thought that this
module would work, too. But problem is in detail.
When we start our program that exchanges data with our server
asynchronously in both directions, the connection after a while (this time is
various) first gets bumby and later stops. I could see that data that is sent
over serial port to the module, is not transfered to the server anymore. And
vice versa data that is sent by the server does not appear on serial port of the
modem anymore. When this state occurs even a ping is not answered anymore. When
startet on the modem the ping-request still is transfered over serial port but
the module does not respond.
The strange thing then occures sometimes up to 2 minutes after program
timeout: suddenly the whole data the server had sent to the modem but didn’t appear
on serial line is flushed over serial port as if it had been in the modules
buffer. This behaviour the GE864 Quad Automotive never showed. Maybe this attitude
is related to a buffer problem of the V2 module?
I also checked the tracelogs of the V2 module. I have found a few
messages that I cannot directly connect to our problem but perhaps someone
FATAL> Mon Activity stopped by DSP
– L1 ERR :
Invalid ptr detected !
WARNING: SY detected reuse of Timer 114 at 1156216
WARNING: RR The value of variable is 10607
WARNING: RR The value of variable is -1
I have made further tests with the WinSCP tool. I transfered files from
and to the modem and had no connection problems. Looking at the data going over
serial port from V2 module to modem and vice versa always showed a big amount
of bytes in one direction before the data-direction changes. The data packages, if our program is communicating with the server, are much smaller than these.
Perhaps the V2 module has buffer-problems if communication direction changes to
fast on serial line?
Like I said, the GE864 Quad Automotive doesn’t have such problems. So I
would exclude server problems on our side.
Software versions are:
GE864 Quad Automotive: 07.03.030
GE864 Quad Automotive V2: 10.00.032
Thanks in advance!
First I would upgrade to 10.00.032 or 10.00.034 if you have access to them, these versions have improvements.
Are you using flow control on serial port? If yes, are signals behaving normally?
I don’t have the new firmware version for Telit GE864 Quad
Automotive V2. But we have a pc-program for flashing the modules. Its name is Xfp Ver_2.0.13 – TDK_2.0.17.exe. Where
can I get the new firmware? I don’t have login-name and password for the telit’s
We don’t use flow control on serial port. But it seems to
make no difference if we use it or not. I configured the pppd with the crtscts-option
but that had no effect. The result was the same.
The V2 module seems to handle data differently than the
predecessor module. With the predecessor module data come more steadyly. But
the V2 module seems to have more pauses between the data packets and then it transfers
more bytes at once over serial port. And at sometime it completely stops
transferring data for minutes. Then it sometimes suddenly transfers a hugh
block of data over serial port after these minutes.Perhaps they have been inside the module’s buffer.
How do I get new firmware, tools and documentation files from Telit?
It seems as if version 10.00.034 would have solved the problem. I will do more tests… .
Thanks for your help!
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