Telemetry Anyone

In addition to ham radio and scanners, I am into amateur seismology. Currently, I an wanting to remotely place my sensors, with out a long run of cable. Searching for suitable telemetry gear seem to fall into the Radio Control people and equipment.

Anyone know of a source for inexpensive telemetry equipment for a constant analog signal?

Thanks,
Jerry

SCADA

Sounds like you may need a simple SCADA system. If you want to monitor one voltage, a simple and cheap, but not real-time solution is a Kantronics KPC-3+ which you can query the voltage from 0-5vdc, I believe.

There are a couple of companies that combine a 900 MHz FHSS radio with a contact closure or voltage points, that replicate what happens at one end, to the other, with relatively low-latency. Typically about $1K or so per end. They work "end to end" without the need of a central SCADA controller.

http://www.scadalink.com/products/wireless-communications/scadalink-modems/

If you want separate boxes for the transport (radio/IP) and interface (RTU) then consider the "Click" line of plc's from Automation Direct.

Thanks Techman. I should have been more descriptive. I've got two seismometers and have to monitor each 24/7 and that would mean two signals into a TX device and a RX device here at home. BOTH would have to be interfaced with the sensors and A/D board in the house.

I am trying to avoid a 250 run of four conductor twisted shielded cable! THAT may end up being my only option. I'm not even mentioning the power supply system that would be required remotely.

Thanks again for reply.

I've heard of people using an audio VCO for remote analog data, like what you get from a seismometer. There are voltage to frequency, and frequency to voltage chips available for a few dollars, if you're up to building something uip. A low power transmitter and a receiver are the easy part.

For that matter, you could directly frequency modulate the transmitter, and take the corresponding variable DC voltage direct off an FM discriminator and use that.