This product is no longer available.

METCON is a device for remote teleMETry and CONtrol. It is based on an 87C51 microcontroller and provides eight (8) inputs and eight (8) outputs.

The inputs can be used for digital monitoring (switch closures, etc.), frequency measurement (up to 10 kHz), and accumulating pulses of longer than 20 mS (number of times a switch opened, drops from a rain gauge, etc.).

The basic METCON package includes 4 output relays, although the board can be populated with a total of 8 outputs. METCON outputs are 'dry-contacts' provided by normally open reed relays. These relay contacts are isolated from the rest of the board (i.e. not grounded) and are suitable for controlling a variety of loads, such as energizing larger relays for power control functions. The additional 4 output relays and their connectors are available from TAPR.

METCON can be connected to a TNC at a remote site and, via a shared packet-radio channel, may measure and/or control operations at the remote site. Applications might include repeater control and weather observations. METCON includes a serial port with three levels of security access:

None - for direct hardwire connection

Password - for dialup telephone modem connection

Authentication - for non-private party-line packet radio connection

Voltage-to-Frequency Module
The voltage-to-frequency module converts analog signals (voltage, current, power, etc.) to a frequency in the range that METCON can read via its frequency counter inputs. The VTF converter is useful for measuring signal sources that are a long distance from the METCON board or that must be electrically isolated from METCON.
METCON-1 VTF Module Schematic

Voltage-to-Temperature Module
The VTT module is a voltage-to-frequency module that includes additional components for temperature readings. Output from the temperature circuit drives the standard input of the VTF module, which then feeds into METCON. Kits are available for either Celsius or Fahrenheit readings.

8-input Analog-to-Digital Convertor
The 8-input A-D convertor module allows for voltage measurements with METCON. The A-D convertor module does not use any of the original eight METCON inputs, giving an additional 8 inputs. Unlike the voltage-to-frequency module, the A-D convertor shares a common ground with METCON and is therefore unsuitable for measurements where ground must be at different levels or separated from METCON by long cables.
METCON-1 ADC Module Schematic

Elapsed Time Pulser
The elapsed time pulser module is useful for measuring things like how long a transmitter has been keyed up, or how long a cooling system has been running.
METCON-1 ETP Module Schematic

Download Metcon Assembly Manual (pdf, 62K)

Download Metcon System Operations Manual (pdf, 164K)

Download Metcon Circuit Description (pdf, 13K)

Download Metcon Memory Display (pdf, 5K)

Download Metcon A-D Assembly Manual (pdf format, 118K)

Download Metcon V-F & T-F Assembly Manuals (pdf format, 82K)

Acknowledgements

Project Designer/Manager: Paul Newland, AD7I