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Counter with increment acknowledge

B

Baroje

Jan 1, 1970
0
Hello!

I need a digital counter which has the ability of sending the
acknowledgement signal on one of its outputs! I need to be 100 percent sure
that counter is incremented when button is pressed or some other event ocur!
When counter is incremented electrical signal must be send to one of the
counter outputs so that some other device can know for sure that the counter
was inrcemented.

Where can I buy counter with this ability or if not how can I modify one of
the existing counters to act like I want and need???

TNX
 
R

Robert Lacoste

Jan 1, 1970
0
Depending on your frequency requirements a microcontroller will do it
easily.

As an alternative you can use a standalone counter with a communication port
(BCD output or even RS232 or GPIB output), and just read the displayed value
with one of these ports to check if a change as happened...

What is the application about ? May be could we help more...

Robert Lacoste
http://www.alciom.com
 
C

CWatters

Jan 1, 1970
0
Sounds like an application for a small micro like the PIC or smaller.
 
M

Michael Black

Jan 1, 1970
0
Baroje" ([email protected]) said:
Hello!

I need a digital counter which has the ability of sending the
acknowledgement signal on one of its outputs! I need to be 100 percent sure
that counter is incremented when button is pressed or some other event ocur!
When counter is incremented electrical signal must be send to one of the
counter outputs so that some other device can know for sure that the counter
was inrcemented.

Where can I buy counter with this ability or if not how can I modify one of
the existing counters to act like I want and need???

TNX
But what don't you trust about the counters that you need this flag?
Unless you have a really odd design (ie there is an input to the counters
from somewhere else so you can't guarantee that each button press does
count), once you've got a good design the counter will increment each time
the button is pressed.

If you don't trust the button press, ie the button is flakey, then
you add circuitry so each time the button is pressed, there is a short
audio beep.

If it's really that you need a strobe for something else when there
is a button press, then you use the button press signal as the strobe.


Michael
 
B

Baroje

Jan 1, 1970
0
Robert Lacoste said:
Depending on your frequency requirements a microcontroller will do it
easily.

As an alternative you can use a standalone counter with a communication port
(BCD output or even RS232 or GPIB output), and just read the displayed value
with one of these ports to check if a change as happened...

What is the application about ? May be could we help more...

Like I said on the other group, it is about distance control. When the
button is pressed and the counter increments someone else who is not in the
same place must know that the increment did ocur. He do not know the state
of the counter, he only need to know that increment was performed correctly!

I don't know how this will work since I don't have a computer present
(RS232).
Do you think it could be done by connecting a reley on that output you are
talking about, and when the increment ocur the reley can for example turn on
the light bulb!
 
B

Baroje

Jan 1, 1970
0
Michael Black said:
But what don't you trust about the counters that you need this flag?
Unless you have a really odd design (ie there is an input to the counters
from somewhere else so you can't guarantee that each button press does
count), once you've got a good design the counter will increment each time
the button is pressed.

If you don't trust the button press, ie the button is flakey, then
you add circuitry so each time the button is pressed, there is a short
audio beep.

If it's really that you need a strobe for something else when there
is a button press, then you use the button press signal as the strobe.


Michael


No.

What I need is a singal from the counter and not from the button. THe
button is pressed OK, I trust that, the counter increments and here I need
confirmation so that for example on same distance, where I cannot see the
counter I know that counter realy did increment. Important thing is that I
do not need to know the state of counter on the distance but only did it or
did it not increment!
 
B

Baroje

Jan 1, 1970
0
CWatters said:
Sounds like an application for a small micro like the PIC or smaller.

I had similar idea but I do not know so much about that problem. Can you
tell me a little more.??

TNX
 
S

Steve Wake

Jan 1, 1970
0
It sounds like you are trying to communicate information instantaneously.
Maybe possible on a useful basis in a couple of hundred years time, but in
the meantime you need to control the expectations of the people who want you
to build a star trek style teleporter.
 
R

Rich Grise

Jan 1, 1970
0
Then monitor the state of the button signal at the point where it
enters the counter. If you can not trust that your counter increments
when it receives that button-press signal, then you have a defective
counter.

It's just that simple.

And what specifically is the application about? Can you describe
what is being counted? Where are these people standing or sitting?
What do they see? That sort of thing. We're all insatiably curious,
you know. :)

Thanks,
Rich
 
R

Richard Crowley

Jan 1, 1970
0
What I need is a singal from the counter and not
from the button.

You haven 't explained why YOU think this is important.
Seems like the obvious answer to most of us.
THe button is pressed OK, I trust that, the counter
increments

In that case the same button-press signal that increments
the counter *IS* your remote signal.
and here I need confirmation so that for example on
same distance, where I cannot see the counter I know
that counter realy did increment.

If you trust the button-press signal, and you trust the counter
to reliably increment, then the button-press signal itself can
be reliably used as your remote indicator.
Important thing is that I do not need to know the state
of counter on the distance but only did it or did it not
increment!

Perhaps you should explain why you think this is ever an
issue. Otherwise we will be going round and round forever.
 
B

Baroje

Jan 1, 1970
0
Rich Grise said:
Then monitor the state of the button signal at the point where it
enters the counter. If you can not trust that your counter increments
when it receives that button-press signal, then you have a defective
counter.

It's just that simple.

And what specifically is the application about? Can you describe
what is being counted? Where are these people standing or sitting?
What do they see? That sort of thing. We're all insatiably curious,
you know. :)

This application is about railway safety. My customers want to have double
security and there is nothing I can do. It needs to be done no mather what.

It is something like this. The trains are passing through the station or the
switch and we are counting them. That's where I need a counter. The counter
is either automaticaly increment or by the railway staff on the station. For
some reason the bastards on the railways want to have a electrical signal
from the counter to confirm its incrementing, they do not want to confirm
the incrementig using the input signal in the counter. They say somethin
like this: " Ok, there is input signal and after that the counter is
incremented, BUT what if there is somekind of error (due to weather or any
other reason) and you have an input signal but the counter does not
increments itself. We want to have independent (independent from input
signal) confirmation of the incrementing"!

It is very important from the safety stand to be absolutely sure about the
number of trains in one rail section!

Thank you for your time.

Hrvoje
 
M

Mjolinor

Jan 1, 1970
0
Baroje said:
This application is about railway safety. My customers want to have double
security and there is nothing I can do. It needs to be done no mather what.

It is something like this. The trains are passing through the station or the
switch and we are counting them. That's where I need a counter. The counter
is either automaticaly increment or by the railway staff on the station. For
some reason the bastards on the railways want to have a electrical signal
from the counter to confirm its incrementing, they do not want to confirm
the incrementig using the input signal in the counter. They say somethin
like this: " Ok, there is input signal and after that the counter is
incremented, BUT what if there is somekind of error (due to weather or any
other reason) and you have an input signal but the counter does not
increments itself. We want to have independent (independent from input
signal) confirmation of the incrementing"!

It is very important from the safety stand to be absolutely sure about the
number of trains in one rail section!

Thank you for your time.

Hrvoje

It's a belt and braces job. You need to install 100% redundancy and
duplicate everything to satify a requirement like that.
 
K

Keith R. Williams

Jan 1, 1970
0
hrvoje.baric_NO_SPAM_@zagreb- said:
This application is about railway safety. My customers want to have double
security and there is nothing I can do. It needs to be done no mather what.

It is something like this. The trains are passing through the station or the
switch and we are counting them. That's where I need a counter. The counter
is either automaticaly increment or by the railway staff on the station. For
some reason the bastards on the railways want to have a electrical signal
from the counter to confirm its incrementing, they do not want to confirm
the incrementig using the input signal in the counter. They say somethin
like this: " Ok, there is input signal and after that the counter is
incremented, BUT what if there is somekind of error (due to weather or any
other reason) and you have an input signal but the counter does not
increments itself. We want to have independent (independent from input
signal) confirmation of the incrementing"!

It is very important from the safety stand to be absolutely sure about the
number of trains in one rail section!

Thank you for your time.

Seems fairly straight forward. I think the answer has been given
before though. You'll need some sort of clock to register the LSB of
the counter. Then compare this register's input and output with an XOR
gate. You'll get a '1' out of the XOR gate for one clock period after
the counter increments. If you really want to look for the entire
counter incrementing you can register the entire counter, add 1 and
compare to the current value of the counter.
 
M

Michael Black

Jan 1, 1970
0
Baroje" ([email protected]) said:
No.

What I need is a singal from the counter and not from the button. THe
button is pressed OK, I trust that, the counter increments and here I need
confirmation so that for example on same distance, where I cannot see the
counter I know that counter realy did increment. Important thing is that I
do not need to know the state of counter on the distance but only did it or
did it not increment!
And what condition allows it to not increment? SOmething in the circuit,
or because the counter has reached the maximum count? If the latter,
then you just watch for that.

Michael
 
C

CWatters

Jan 1, 1970
0
This application is about railway safety. My customers want to have double
security and there is nothing I can do. It needs to be done no mather
what.

What would happen if the counter made a spurious extra count? For example
train systems are noisy environments (lots of high currents and voltages
flying about). If you have long wires it wouldn't be hard for noise or
perhaps a local lightening strikes to cause "extra" phantom button presses.

I suggested using a small microprocessor in an earlier reply and now I'm
going to suggest you use TWO!

Let's call them the "Button micro" and the "Counter Micro" - put one at each
end of the wire.

Arrange it so that both microprocessors maintain the same count. When the
button is pressed the "button micro" increments it's count and sends a
packet of information down the wire. The packet could contain the new count
and perhaps a message telling the counter to increment or decrement it's owb
copy. The counter micro should increment it's counter and compare the result
with what the button micro said. If they agree then the Counter micro can
send an acknowledgement message back to the Button micro to say "I got that
one thanks". Add some extra code and it's easy to ensure that both micros
check each other is working ok. They can even send each other test messages
when no button presses occur just to check the wire isn't broken or the
power failed at one end (eg "you still awake messages?) .

If there is a power cut at one end it can even ask the other end what the
last count was when power is restored.

Many micro like the PIC series have UARTs or serial interfaces of other
sorts in them to make this easy.

The system could also be made expandable. For example what happens next
month when they change their minds and want TWO buttons and two counters but
you have already installed only one wire? It's simple you just make the
counters addressable and they share the wire. Many micros have addressable
serial interfaces for this sort of thing.
 
C

Colubris

Jan 1, 1970
0
Baroje said:
Hello!

I need a digital counter which has the ability of sending the
acknowledgement signal on one of its outputs! I need to be 100 percent sure
that counter is incremented when button is pressed or some other event ocur!
When counter is incremented electrical signal must be send to one of the
counter outputs so that some other device can know for sure that the counter
was inrcemented.

Where can I buy counter with this ability or if not how can I modify one of
the existing counters to act like I want and need???

TNX

What about a mechanical counter? Less prone to misfires from
electrical "noise", cheap, durable.
Maybe put a microswitch inside the counter that gets hit by the
mechanism inside the counter. If the microwsitch gets a closure at
each count, you know the counter actually incremented. Could maybe use
two counters for redundancy.

Arch
 
R

Richard Crowley

Jan 1, 1970
0
It's a belt and braces job. You need to install 100% redundancy
and duplicate everything to satify a requirement like that.

There are new problems with completely redundant systems.
What happens if the counter circuig fails, but the redundant
"confidence indicator" circuit works?
 
R

Richard Crowley

Jan 1, 1970
0
What about a mechanical counter? Less prone to
misfires from electrical "noise", cheap, durable.
Maybe put a microswitch inside the counter that
gets hit by the mechanism inside the counter. If the
microwsitch gets a closure at each count, you know
the counter actually incremented. Could maybe use
two counters for redundancy.

Exactly what I was going to suggest.
It pays to read the entire thread before responding! :)
 
R

Rich Grise

Jan 1, 1970
0
How much money do these people have? What kind of display? Point
an array of photodiodes, or a CCD camera at the displays, and
analyze its output. When one of the digits changes, you've
counted. Actually, you only need to watch the LSB. Maybe
a tiny photodiode very close to each LED segment. If it's
an LCD, then you'll probably have to look at the input
signals, unless you have a photosensor that can read an
LCD. Otherwise, tear into the circuit and monitor the
outputs of whatever's driving the display.

I'd be cheaper to hire bonded employees.

Good Luck!
Rich
 
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