Low Battery Indicator; Series Operation; Parallel Operation - Wavetek 75 Instruction Manual

the waveform output. In all other modes the generator
will be waiting for a trigger after the ramp to restart the
waveform output.
3.23 LOW BATTERY INDICATOR
If the internal lithium battery runs low, the top line of the
display will display "BAT" in addition to the normal
message when a menu key is pressed. The low battery
will not effect normal operation as long as the power is
not turned off. If the power is turned off the instrument
could lose all of the stored waveforms, setup informa-
tion and calibration constant. If, when the power is first
turned on, the bottom lineof the display reads "**COLD
START* *", all of the memory has been lost due to a low
battery and the instrument will need to be calibrated and
set up again.
3.24 SERIES OPERATION
Several Model 75's can be connected in series (as shown
in the following diagram), each one generating one or
a burst of waveforms (see figure 3-4) and then trigger-
ing the next Model 75 in the chain. The outputs can be
added together using the "Sum In" inputs to produce
one waveform that is a chain of each of the individual
waveforms in succession. This configuration can be us-
ed to create waveforms longer than the 81 92 sample
maximum or to create a series of normal waveforms
followed by one or more abnormal waveforms.
MODEL 75 #I
w - .
1
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- - -
/
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@ @ P o p ,
OSClLLOSCOPE
I
BURST DONE
OUT CH 2 IN
MODEL 75
#2
0
@
-
-
r -
=
r
-
BURST
b
TRIG IN DONE ARB OUT
OUT
L
SUM IN
first. The "ARB Out" connector of each instrument is
connected to its successor's "Sum In" connector and
the last "ARB Out" connector is used as the main out-
put. Each of the Model 75's can have independent
waveform sample frequencies if desired, but if this is not
necessary, one should be used as the master frequency
reference. Todo this, connect the "Ref Out" connector
of the master frequency reference to the "Ref In" con-
nector of all of the other Model 75's and set them for
external reference. By doing this, the one sample time
jitter between successive waveforms is eliminated.
MODEL 75 #2
Figure 3-4. Example of Series Waveform
Each Model 75 should be set to either triggered(if it will
be outputting one period of its waveform) or burst mode
if it will be outputting a sequence of waveforms. The
amplitude control of each Model 75 controls not only its
own amplitude but the amplitudeof theoutput due to the
"Sum In" signal. A
k
5V signal at the "Sum In" input
produces an output equal to the amplitude setting. To
maintain linearity, the sum of the internal waveform and
the "Sum In" waveform should not exceed the amplitude
setting. In equation form:
where W is the internal digital data (Y) value and S is the
voltage at the "Sum In" input at any time. Because of
this, attention needs to be given to the output voltage
at the break point location at the end of each waveform.
Toconnect several Model 75's in series, the "Burst Done
3.25 PARALLEL OPERATION
Out" connector of each Model 75 is connected to its
Several Model 75's can be connected in parallel (as
successor's "Trig In". If the waveform is to run con-
shown in the following diagram) to produce simultaneous
tinuously, the last Model 75's "Burst DoneOut" connec- waveforms (see figure 3-5) with a controllable phase
tor is connected back to the "Trig In'' connector of the relationship.
Scans by Artekhledia O 2006