Hi John,
The active high/low label applies when the circuit or device
is actually on. On meaning the state of the logic... not just
power supplied to the circuit.
The output of a typical logic circuit, gate or device is at
or very near ground or zero volts when it's on... "active low".
When the output voltage from an on logic circuit, gate or device
is at or near the (positive) + supply voltage it's "active high".
"True" is just another old time way to say "active" or "on".
****
The active high voltage can be different values depending on the
circuit. In days of old TTL IC Chip circuits... the chips run off
+5vdc so the high state measured voltage was often ranged anywhere
from about +2.2 volts up toward the +5 volt supply.
A newer generation CMOS IC Chip circuit might often run on a higher
supply voltage... say +12vdc so the high state measured voltage
range might be anything above +6vdc up to the +12vdc value.
In the case of a simple transistor circuit... the classic
"pull-up resistor" tied from the collector to a positive "+"
voltage determines the active high voltage. Not super critical
in common bi-polar transistor type logic circuits because you
need only a small voltage to turn-on the transistor... so in
reality almost any + voltage above about .7 volts starts to turn
the transistor on.
As described...
Your receiver cos logic is on with a strong received signal, the
output is at or near zero volts which is active low.
The ACC controller is setup for active low operation... be aware
that some ACC Controllers don't have an internal pull-up resistor
so you might need to add one. Else with a voltmeter you might not
see the logic at x-location change state with an active receiver.
cheers,
s.
> "John Transue" <[EMAIL PROTECTED]> wrote:
>
> After reading and re-reading the manuals, I am still not 100 percent
> certain what COS high and COS low mean. Please straighten me out.
> When the signal is strong, greater than -100 dBm, the COS logical
> output is zero volts.
> When the signal is less strong, less than -110 dBm, the COS logical
> output is +10 volts.
> Is this "COS active" LOW?
> Using the terminology of the ACC RC-96 owners' manual, is this "RCVR
> COS" LOW TRUE?
> Thanks for the help?
> John Transue
>
