User's Manual

RVP8 User’s Manual
October 2005
TTY Nonvolatile Setups
3–29
PinMap Table (Type ’31’ for GND, ’30’ for +5)
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Pin01:00 Pin02:01 Pin03:02 Pin04:03 Pin05:04
Pin06:05 Pin07:06 Pin08:07 Pin09:08 Pin10:09
Pin11:10 Pin12:11 Pin13:12 Pin14:13 Pin15:14
Pin16:15 Pin17:16 Pin18:17 Pin19:18 Pin20:19
Pin21:20 Pin22:21 Pin23:22 Pin24:23 Pin25:24
FAULT status pin (0:None): 0, ActLow: NO
These questions only appear when the “PinMap” uplink protocol has been selected.
The table assigns a bit from the encoded numeric word to each of the 25 pins of the
RVP8/DAFC module. For example, the default table shown above simply assigns the
low 25 bits of the encoded bit pattern to pins 1-25 in that order. You may also pull a
pin high or low by assigning it to +5 or GND. Note that such assignments produce a
logic-high or logic-low signal level, not an actual power or ground connection. The
latter must be done with actual physical wires.
One of the RVP8/DAFC pins can optionally be selected as a Fault Status indicator.
You may choose which pin to use for this purpose, as well as the polarity of the
incoming signal level. Note that the standard RVP8/DAFC module only supports the
selection of pins 1, 3, 4, 13, 14, and 25 as inputs. This setup question allows you to
choose any pin, however, because it does not know what kind of hardware may be
listening on the uplink and what its constraints might be.
Burst frequency increases with increasing AFC voltage: NO
If the frequency of the transmit burst increases when the AFC control voltage
increases, then answer this question “Yes”; otherwise answer “No”. When this
question is answered correctly, a numerical increase in the AFC drive (D–Units) will
result in an increase in the estimated burst frequency. If the AFC loop is completely
unstable, try reversing this parameter.
Mirror AFC voltage on– 0:None, 1:I, 2:Q : 0
AFC/MFC can be mirrored on a backpanel output of the main chassis using this
question. When either “I” or “Q” is selected, the AFC/MFC voltage will be present
on the corresponding BNC output, and the other output will be used for scope
plotting. This configuration would be useful, for example, in a dual-receiver
magnetron system that needs a phase locked acquisition clock in the RVP8/IFD, but
also needs an AFC tuning voltage to control the transmit frequency. When “None” is
selected, scope plotting will revert to its normal “Q” output.
The voltage range of the “I” and “Q” outputs is approximately 1 Volt, and is not
adjustable. When AFC/MFC is mirrored on these lines, you will probably need to
add an external Op-Amp circuit to adjust the voltage span and offset to match your
RF components. We also recommend that you add significant low-pass filtering
(cutoff at 3Hz) to remove any power line noise or crosstalk that may be originating
within the RVP8 chassis.