atcomsystems.ca/forum Forums Computers & Programming Computers, Software, Accessories Internet connection lost relay

I have constant problems with my modem failing, causing my server to go offline. I'm wanting to somehow set off a 12v relay when the connection is lost. The LAN doesn't go down, just the modem send/receive.

So, if there is a device that could:
ping google.com
if google.com not found
then activate relay

Activating the 12v relay would cause a building buzzer to go off to notify staff that the system is offline.

Anyone know of such a solution?

It is an external dial-up modem? If so, the CD (carrier detect) lead will be held high (+5 volts I believe) as long as the connection is live. You could use that to drive a VERY low current relay using pin 5 (on a 9-pin) or pin 7 (on a 25 pin) connector as the ground for the other side of the relay's coil. Once you drive that relay, you can do anything you want with the contacts.

As for pinging, I don't know what you could do except to possibly use it to start up another machine with the appropriate script in the startup menu. I am just grasping at straws here.

If it is an internal modem, I don't have any suggestions.

It's a cable modem actually, I wish it were a dial-up, as I have one with built-in relay.

I found a program that would run on a seperate machine and blare from the speakers when a ping isn't detected. That might be the only way to go.

Thanks for the input though, Ed

Well, I feel like an old-school retard now! I should have known better than to think it was a dial-up modem. Oh well, maybe someone else might be able to use that idea (or laugh at it) in the future.

Also reaching at straws....
but thinking that by software many programs that don't see internet connectivity automatically goto a secondary dial up land line modem for connectivity. Can't it be set it up to goto the dialout modem the same way and change the dial string to call out to a cell or a manned position?

Just thinking it through.

topher -

Do some searches for simple homebrew circuits that will allow you to trigger logic or relays from a PC serial or parallel port. There are also commercial devices designed for this too, either USB/ Serial/Parallel, or internal boards.... Then just write a quick program to ping, parse the output and then trigger the relay code if necessary.

BTW, I''ll just wet your appetite - the Parallel port is easy, and you have 8 data lines, that only need a single Output to the port address to trigger and hold a value.... In VB Out(&378, &1) will hold data pin 1 high (with the default port address 378h).