Counter/Timer

cancel
Showing results for 
Search instead for 
Did you mean: 

flowmeter on usb 6009 (connections)

Hello,

 

I am using a flowmeter (attached) on a USB 6009. The wiring connections (3 wires from flowmeter) are:

Sig ground to GRD of the module

+Vdc to the +5V of module

Signal output to the PFI0 of module.

This configuration was already fixed (it works fine with the labview program) by a previous staff member no longer available. 

The question is, in case I get one more flowmeter like this, is it possible to connect it on the same module?? What the wiring connections could be in this case??

 

 Thank you in advance!

 

0 Kudos
Message 1 of 6
(5,118 Views)

You should be able to, just use a different channel for the signal.  You should also be careful about your current on the 5V line.  You may want to concider using another power supply.


GCentral
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines
"Not that we are sufficient in ourselves to claim anything as coming from us, but our sufficiency is from God" - 2 Corinthians 3:5
0 Kudos
Message 2 of 6
(5,110 Views)

So, I will have the two wires from the two flowmeters going to GND (common) and different channels for the signal. My consideration is the 5V line as you said also. In case of having both sensors on that line is possible not getting 5V for each sensor which is required?? That's why you are suggesting different external power supply?? 

 

Thank you for your reply! 

0 Kudos
Message 3 of 6
(5,108 Views)

@chotzkon wrote:

So, I will have the two wires from the two flowmeters going to GND (common) and different channels for the signal. My consideration is the 5V line as you said also. In case of having both sensors on that line is possible not getting 5V for each sensor which is required?? That's why you are suggesting different external power supply??


Yes, all grounds (common) need to be tied together.

 

The 5V could be limited by the current in two possible ways: a fuse or a current limiter.  If it is using a fuse and you draw too much current, the output is completely shut off (blown fuse breaks the circuit).  If it is a current limiter, then the output voltage will drop when you reach the current limit, which could cause some weird oscillations on the power line or you just do not have enough voltage to power your sensor.  So I recommend using an external power supply that you know can handle the current.  There are plenty out there that you could get fairly cheap.


GCentral
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines
"Not that we are sufficient in ourselves to claim anything as coming from us, but our sufficiency is from God" - 2 Corinthians 3:5
0 Kudos
Message 4 of 6
(5,105 Views)

thank you very much!!! I will follow your suggestion.. I will post any result for similar questions!!

 

Cheers

0 Kudos
Message 5 of 6
(5,103 Views)

I am not sure you can use multiple flowmeters that way on the USB-6009.  I am not sure you can even use one flowmeter with reliable results on a USB-6009 that way.

 

1. The USB-6009 has only one PFI input. It can be used as an event coutner input or a digital trigger.

2. The USB-6009 has only one counter and it can be configured only as an event counter.

3. That means that the count interval will be software timed, resulting in substantial jitter.

 

Since your flow meter only generates relatively low frequencies (<300 Hz), you could use analog inputs and process the results in software.  Then you could use up to 8 flowmeters with one USB-6009. 

 

As crossrulz pointed out, you may need an external power supply. The so-called data sheet you posted does not sepcify the power consumption of the flowmeters.

 

Lynn

0 Kudos
Message 6 of 6
(5,061 Views)