turbine flow meter conversion

[Carl.G]

Hi,

Apologies for the query but this software is all new to me . I have a 9188 cDaq 8 way chassis containing several modules including 2 off 9401 counter modules, I am running signal express version 6.0.0. 

My issue is I have 3 miniature turbine flow meters (Gems units FT-110 series) which are giving out 5V square waves at varying pulse widths dependant upon what the flow is.  I've scoped the input to my 9401 and the signals look good so am assuming it's my signal express configuring that is causing the problem,

I've wired the +ve and gnd outputs of the flowmeters to DIO0 +Com, DIO1 + Com and DIO3 + Com on one of my 9401 cards.

I can see the pulse count increment on measurement & automation explorer when I run the test panel for that module and look at the edge counts so my system can see the pulse trains coming in.

When configuring signal express I need this to read in l/min, 58-575Hz should equate to 0.5-5 l/min, however I cannot seem to convert the pulses to l/min.

If I select DAQmx acquire>counter input>frequency it gives me the option of custom scaling but every time I run it I get the DAQ assistant error flagging up.  I tried numerous timing settings with no luck.  The only time I've got this to count succesfully is using counter input>edge count but I'm stuck on how to convert this into l/min as there is no scaling function (that I'm aware of!)

Any help appreciated.

[Kev_R]

Hi Carl.G, 

My nameis Kevin and I am an Application Engineer at NIUK. 

I have a few questions for you:

1. What is l/min?

2. What is the error you are seeing? (Perhaps post a screen shot)

Kind Regards

[OKors · Accepted solution]

I think he's referring to l/min as Liters per minute, and i'm assuming the Freq to Flow are the values that corrolate to the scaling.
If that's the case; Carl, it sounds to me you need to setup a custom scale. You can do this in the Channel Settings tab in the DAQmxAcquire step. Under custom scaling select Create New and select Map Range Scale. You min/max Freq should equal your min/max flow rate.

I've attached some screenshots for reference.

Let us know if we're on the right track, otherwise we may need more info; I.E. .seproj file and a bit more info on the flow meter (connection type, output signal, etc).
Also, a brief glance at the documentation on that flow meter recommends the use of a pull-up resistor. May want to look at that as well.

[Carl.G]

Thanks for the responses.  Now sorted after those screenshots and using the correct scaling configuration.  

[guttasandeep22]

Dear Sir,

     I am using a flow meter which consist of 3 wires i.e. brown, yellow, red

Brown== Vout

Yellow== ground

Red== Vdd

and i am using C-DAQ 9219 module

 i need help i.e. how to connections to daq

so please help me to take the readings

[OKors]

Lots of missing information here, but to start with the 9219 is an Analog input module. You would tie brown and yellow to one of the channels of this module.
You would also need to supply voltage to the sensor, either through a power supply (not ideal) or an analog output module capable of supplying a steady current out to your sensor. that would be your red and yellow. Yellow would be common between your Vout and Vdd.

Scaling your sensor in Signal Express would be next but without any information we cant help.
Get your supply voltage figured out and if you need further help post a link to your sensor's model number.