Dear reader,
We have used the WP7610 for some time now. With success, although we needed to set the modem image from ‘Verizon’ to ‘Generic’ as our devices are scattered around the North American continent.
Now the WP7610 is replaced by the WP7611 because the former is hard to buy. Learning from the last time (since we’re in Europe), we haven sent first one sample to the USA for testing purposes. Of course, we made sure the modem works, and has the ‘Generic’ image active. But, due to no support of the modem for the European frequency bands; real testing will be in the USA. A remote laptop access is included such that we can access the device over it’s ethernet connection in case connection fails.
The device itself will make a PPP connection automatically and has a webserver which we can access over VPN. Also, we can access the device using SSH over VPN. In addition, the device will transmit data now and then. This device is the same as all other devices but with a WP7610 modem. The only difference is the WP7611 modem.
Well, I would not be here if there were issues. After a couple of times, we discovered we could access the device right after boot, but only for about 30 seconds or so. Later I found out that, if I brought the PPP interface down and up over the remote laptop connection, I could access it again, but only for a short time.
This lead me to believe there were some routing issues; but they were OK.
After some time I just made a test with a specific webpage that has a refresh button. Clicking on that will refresh the page each 2 seconds. I left it there for a few minutes, expecting that the connection breaks within a minute or so… But no… the connection was fine. Even after an 10 hours with no activity from my side, accessing is now without issues.
We did not change much. The chatscript has an AT command CFUN=1. We also tried that manuall off and on, with no difference observed. Also, we could not get the device back in it’s original state where it breaks connection after 30 seconds or so.
How on earth is it possible that, first connection breaks 30 seconds after getting online, and later it just remains open?
What has caused that? What are possibilities that connection breaks in 30 s?
Anyone with some hints will be much appreciated.
Cheers,
AJ