METCON
------
(Limited Supply)

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.


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.


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.


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Tucson Amateur Packet Radio Corp.
8987-309 E Tanque Verde Rd #337 * Tucson, Az * 85749-9399
Phone: (817) 383-0000 * Fax: (817) 566-2544

TAPR is a Non-Profit R & D Corporation
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