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SCC-A10 For Simple Voltage Measurement

SCC-A10 For Simple Voltage Measurement

Hi

I have a NO laser proximity sensor (can be changed to NC) that has a supply voltage of 24V. If I wish to measure the output, which swings between 23.3V and 0V, would the SCC-A10 be a viable module to use? I require a somewhat fast sample rate (sensor has a switching frequency of 1.1kHz and a response time of 455us), but I only require in the 100s of Hz.

As well, as the output of the sensor is only one wire, would I have to connect the neutral of its power supply to the ground of the module? The power supply does not have a ground.

Anything else I should know?

Any help is greatly appreciated, as I am no expert when it comes to electronics.

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Re: SCC-A10 For Simple Voltage Measurement

The SCC-A10 should be fine, but it does not perform any acquisition, so you will still need something like a DAQ card.

 

You will be wiring measurement to a grounded signal source. The power supply should have a ground or negative terminal, any signal will require at least two connections so you can complete the circuit. You can attach it as a differential or NRSE, but if you wire between the two systems' ground then you may cause a grounding loop. With the SCC-A10 you can probably use differential mode. We have a very in depth description of wiring here.

- Regards,

Beutlich
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Re: SCC-A10 For Simple Voltage Measurement

Thank you for the reply, was fearing I was going to be left to my own devices (and probably destroying them).

I have a laptop DAQ card, the 6036E to be specific. And the SC-2345 obviously.

That is quite the description of wiring. Am I correct if I connect the output of the sensor to the positive input of the module, and leave the negative empty, it will reference it to the ground of the SC-2345? I do not need a very specific voltage measurement, I am only looking for a change from open to closed and back again (really fast).

Is there any way to do what I require using a low-pass filter module (of which I already have some), or without any module and just the SC-2345?

And one last question: What is the return policy for modules? If the sensor does not work for the application, can I return the module if it has only been used once or twice?

Thanks again for any help (lots of questions I know).

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Re: SCC-A10 For Simple Voltage Measurement

Am I correct if I connect the output of the sensor to the positive input of the module, and leave the negative empty, it will reference it to the ground of the SC-2345?

Actually, that is not quite right. Looking more closely at this module, the SCC-A10 seems to only do differential. The voltage will be measured as across pin 1 and pin 2 or between 3 and 4.if you don't wire anything to the negative terminal on this pin, you will be comparing the voltage to a floating node (random noise), and will get terrible data. If you look at the figure from the user manual for the SCC A10, notice that the grounds are separated. You can wire the ground of you laser device/power supply to the negative terminal, and that will give you the voltage reading appropriately.

 

SC2345 Fig 1.png

 

Is there any way to do what I require using a low-pass filter module (of which I already have some), or without any module and just the SC-2345?

You certainly can use a low-pass filter, although if your signal is changing fast, that will not pass through the low pass. Also, it might not have a built in differential amp in it, so you would need to consider how that module should be wired.

You can also use the break out connectors inside the 2345 to wire straight to the DAQ board. There you can set it up as either differential or NRSE, and I would advise NRSE. So, for instance, you can wire your signal to pin 3 (AI 0), and pin 19 (AI Sense) to the ground of your power suppy/laser device.

 

You should contact a sales representative to ask about details on purchasing, exchanges, or similar questions, and he will be able to give you the relevant details on your account.

 

- Regards,

Beutlich
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Re: SCC-A10 For Simple Voltage Measurement

Thank you again for the response, the fact that I may not have to purchase a module makes me quite happy!

When you say the break out connectors, are you speaking of the connectors where the modules plug into, and if so, should I be connecting the input and neutral as per the following picture?

pinout2345.JPG

 

Image taken from SC-2345 manual: http://www.ni.com/pdf/manuals/371064f.pdf

Would I therefore connect the input to pin 1 (AI (X) to DAQ device) and neutral to pin 3 (AI SENSE) on one of the J1-J8 connectors? I don't need to worry about blowing the sc-2345 at all do I?

I highly appreciate the help you are giving me with this, as it is saving me a lot of time, hassle and money. Thank you.

 

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Re: SCC-A10 For Simple Voltage Measurement

The SC 2345 have terminal blocks on the side (not where the modules plug in) which are straight feed throughs to the DAQ board. The terminal block connectors bypass the signal conditioning on the SCC so you can access the DAQ board directly. This means that you can put crazy voltages on the device, and the SC 2345 would probably be fine but the DAQ device would become toast. You would need to verify that your signal is within the voltage and current for the 6036E, otherwise you can damage the device inside yout PC. If the signal you are measuring is too big, then some signal conditioning (thus the signal conditioning connector block, or SCC block) would be necessary/desireable. You may also want to find a EE friend to help talk out some of these things if voltage levels are going to be a problem and you don't feel comfortable with the wiring concepts.

- Regards,

Beutlich
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Re: SCC-A10 For Simple Voltage Measurement

I thought you were talking about the terminal blocks, but I could not find the connections you were talking about:

terminalblock2345.JPG

There is an AI SENSE, but no AI 0...

When I looked at the 6036E manual, it says up to 10V, but the minimum voltage for the sensor is 10V, so I think that dream is dead. SCC-A10 it is.

Thank you for all the help.

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Re: SCC-A10 For Simple Voltage Measurement

Oh you are right, I mixed up the 50-pin connector with the 68 pin connector. How embarassing.

 

Glad I could help!

- Regards,

Beutlich
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