Digi module design problems:
My company has used
several Ethernet to RS232 converters and have designed one which fits
into it's product line and reduces our costs. The latest design uses
the Digi module DC-ME-01T-S, which is a self contained Ethernet to
serial converter. All that is needed is a power supply and a 3.3 volt
to RS232 converter to complete the interface.
The Digi module is
really nice in that it has an IP stack built in, and using it's web
interface, you can log onto it and set it up to be different types of
interface. We used it as an Ethernet bridge.
In our setup, we change the port to 3001, and set the TCP keep alive bit, among other things.
One
of our customers had a disconnect of all our control boxes and none
would reconnect until power to each device was removed and restored.
After much investigation, we found that something had broken the
connection, and that the Digi module decided it was still connected,
but wasn't. The other end of the connection decided nothing was there
and refused to reconnect.
After consulting with Digi tech
support, they advised setting the time out to it's minimum value, which
made the Digi module reboot after determining it was not connected.
This went from about 15 minutes to 30 seconds. The real time was more
like 5 seconds to determine a disconnect and reboot.
We allowed
the system to run for an extended time, and we noticed that the Digi
modules rebooted on a regular basis every 22 hours and 30 minutes. We
again consulted Digi, who refused to assit us any more until we bought
their test fixture, unsoldered a module, and tried it in their test
fixture. Our testing was a quantity of 5 modules were all rebooting at
regular intervals with no communication on the network.
Our next
step in the process is to hook up a Digi module built several years
ago, to see if it also reboots. If not, we will know that Digi has made
a change and that it has a problem.
If you have a solution to this problem, please contact me, and then tell Digi you have a solution. |
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Contact Info:
work 614-851-1100
email:
eplurib@earthlink.net
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Charlie Morrison
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