Hi. My name is Jim Durr, and I'm an application support engineer for Agilent Technologies.
A common question I get regarding the 53200 Series counter is its ability to measure consecutive
cycles from an input pulse stream, and what I'm going to demonstrate is how we can do that.
The answer is, when asked that question, can we measure consecutive cycles?
The answer is really yes and no, and let me demonstrate by what I mean. What I've done is
I've preloaded a burst sequence from the 33500 Series function generator, and what this function
generator is going to do is going to output a burst of ten pulses, and what we're going
to do is attempt to measure those ten pulses using two different modes of the counter.
So, again, with the function generator preloaded using the front-panel host port of the counter,
I'm going to go ahead and take advantage of the ability to load a pre-saved or pre-stored
state that will set this up for the measurement. So in doing so, I simply insert the thumb
drive, and I shall recall the state.
Okay. So I've got the counter preloaded with the
state ready to make the measurement. The first measurement I'm going to make involves using
the counter within the auto mode. By auto mode, first I will set the auto mode.
By auto mode, that implies to how the gate of the measurement is handled with the counter,
and what we mean by that is within auto mode, there is a gate open/gate close sequence
for each measurement in my reading count. So, for example, the gate opens, the trigger
comes in, the gate opens, I begin the measurement; the gate closes, I complete the measurement.
The next trigger comes in, I open the gate, make the measurement. The measurement is done,
I close the gate and so on. In continuous mode, which is the second of the two modes
that I'm going to demonstrate, what happens is that once the trigger is received, there
is a gate open for the first reading. The gate remains open for each subsequent reading,
and then closes once all readings are taken. What that does is that eliminates the gap
in between consecutive readings, and allows us to measure consecutive input cycles.
So with having said that, I will go ahead and I will press the trigger to input -- or a
couple things first. The first thing when making any type of measurements, especially
measurements that are slow, the signal that I'm measuring has a two-second period.
Something that is overlooked, but is very important, is to set the measurement timeout. The measurement
timeout is the period that we allow the counter to make the measurement before timing out
and continuing with the next measurement. So a good check, and something to always note
is when storing or recalling a state, the measurement timeout setting is not preserved
in your stored state so you want to be sure that you're able to check that setting.
So very quickly before this, I check utility instrument setup, timeout settings, and as
you can see, I have turned timeout off. This will give us an indefinite amount of time
for the measurements to complete. So with that set, I am then going to go to the graph
mode, and I'm going to enable the trend chart feature of the counter. With the trend
chart enabled, I'm going to go ahead and press the trigger key. Once I press the trigger
key, I will go ahead and start inputting it in a series of ten input cycles to the counter.
One thing that I wanted to point out as well is I'm externally triggering the counter
from the function generator. So when I press the trigger key on the function generator
to trigger the output, the function generator, in turn, is triggering the counter. So now
I'm going to go ahead and press Trigger to input the signal into the counter, and
what you're going to notice is there's a momentary delay as the counter is requiring
a certain number of cycles at the beginning in order to establish the measurement.
You can see now the first reading of approximately two seconds has occurred. Our reading count
is one, and as we continue on and wait for the next number of cycles to occur, and our
reading count is two. Now keep in mind that what we have done is we have programmed the
function generator to give us ten cycles. We are in the auto mode of the counter.
Auto mode, again, there is an open and close gate sequence for each reading. What is happening
is for all these cycles, for each gate sequence, there's an additional number of cycles that
are required in order to produce the reading. As a result, we've only been able to take
with auto mode two measurements of the ten cycles that were coming in. To alleviate that,
we switch to continuous mode, where as I had described it before, we have one gate open
and one gate close sequence, and all of our trait readings are taking in succession in
the middle. So to show that I will go back, and I will change the reading mode from auto
to continuous. Okay. Now that we have seen the number of readings taken within auto mode,
I've changed the configuration to continuous mode. I'm going to trigger the function
generator, and again, you will notice in a moment the readings will continue to occur
in continuous mode. We've established our first reading, and then what you are seeing
is we've already exceeded our two reading. We are now at five readings, and we will go
to continue to about seven readings. Now, still, there are eight readings, rather.
Still, this is not the point of the ten readings that we had hoped to accomplish, but what
we were able to see is within auto mode we only were able to achieve two readings. Here
we have been able to achieve up to eight readings, and the reason why was that the first couple
of cycles were required to establish the first reading, two cycles in this instance, leaving
us two readings remaining to complete our total of ten readings. So to alleviate that,
I can go back to the function generator, and I can set the number of cycles. I will set
it to a number larger than ten to account for the number of cycles that are required
to establish the first reading. So now I have set the number of cycles to 13. I'll clear
my readings, reading storage. I will preset. I will recall my state to make sure that everything
is clear and initialized. Again, I am in continuous mode. Now I've got 13 cycles programmed
to come into the counter, and my counter is expecting to measure ten cycles consecutively.
I will go ahead again and turn on the graph, the trend chart, trigger the counter, and
momentarily you'll see the first reading begin. There's reading one, and then at
every two-second intervals you'll see my reading count continues, and ten. And there
you can see I've completed the full ten readings that I was expecting to measure.
What I had to account for was the fact that on the first reading it requires multiple
cycles of the input signal in order to produce the first reading. Once that first reading
is taken, then in continuous mode within one continuous gate open/close sequence, I'm
able to go ahead and take successive readings back to back to back on each of the ten cycles.
So although the function generator output 13 cycles, the first three cycles were required
for the first reading. I was then able to pick up consecutively the remaining ten cycles,
as is indicated by my reading count shown on the display. Thank you.