Place the grey customized meters behind the antenna control console where
you can plug them (via supplied ground busters) into a clean mains
supply. Connect the signal cables from the inclinometers to their
respective meters.
Switch on the meters. With the inclinometers essentially horizontal,
the meters should show numbers reflecting this, being between -1000
and +1000. If the inclinometers are tilted excessively the meter readings
will saturate at values of -1 or +1.
At the back of the meters plug in the small cables to the ports labelled
Ext.Sig. , and connect the other ends (BNC) to the (coded BLACK) JCMT
cable system ports RG59-01 (for No.2264) and -02 (No.2267) on the
nearby
patch panel.
The JCMT cabling system takes the signals from here to ports with the
same numbers, but in RED - on the right hand nasmyth - to BLUE - on the
left nasmyth - to BLUE on the computer room patch panel. From here they
should be connected to TNC-09 and TNC-10 respectively, and you should
now locate these on the control room side of this patch panel.
It is really only necessary to connect these to the RxH micro, but since
this micro accepts positive voltages only, the signals are passed through
the signal offset box to allow DC offsets to be applied if necessary.
It is also convenient to tap the signal here for purposes of display on
the chart recorder. Connect TNC-09 to input A on the signal offset box.
Connect output A from this box to the green chart recorder pen and
also to the IP7 port on the patch panel. From here it is taken to the
RxH micro input port labelled amplitude. TNC-10 should be connected
similarly to signal offset box input B, and the output to the red pen and
to IP4 from where it goes to RxH input phase.
The VAX software reads and stores the signal in the amplitude
channel as INC_1 and that in the phase channel as
INC_2.
This scheme is summarized below :
On the RxH micro front panel set the time constant and gain on both
channels to 25 ms and MAX (= 10 turns), respectively.
Chart recorder settings of 100mV are suggested for a meaningful display.
Adjust the signal offsets and the pen position as necessary to give
both a useful display, and sensible input values to the RxH micro.
You ought to do INC> INC_GO tests to confirm that display
settings DO give sensible micro input values.