import to labview signals from equipment

[ABSA]

Hi,

I'm a newbie in labview

I want to import to labview 4 signals from equipment that have the following outputs:

- 4-20mA Pressure signal;

- 4-20mA Flowrate signal;

- 4-20mA rotation speed signal;

- 4-20mA Torque signal;

I have this 4 signals in RS232.

What's the better way to import this data to labview?

Thanks advance

[Dennis_Knutson]

A 4-20ma signal is not at all the same as RS232. Please explain what you actually have. Four separate current signals would require a DAQ device and four separate RS232 signals would require four com ports on your pc.

[ABSA]

thanks for the answer.

I am using an RS232 port but still do not know what the communication protocol.

Maybe use Labview may be too advanced program for what i want. 

I'm trying to recover the acquisition of old equipment.

[DanRen_IQA]

I have found that a very simple and cost effective way to monitor 4-20 mA current loops is to take the current through 250 Ohm resistors across the analog inputs of a data acquisition device (such as an NI USB-6008). This results in a voltage swing ranging from 1 to 5 Volts. Then, a simple DAQmx operation in LabVIEW is used to read the voltage at the data acquisition device. The voltage measurement is then easily scaled to represent the quantity being measured by the instruments generating the currents.

Hope this helps.

Dan

[Sam_Sharp]

I think you need to post some more information about the equipment you are using...you have 4 sensors with a 4-20mA current output - these need to be connected to some sort of data acquisition device that can either measure current directly or measure voltage (with an appropriate resistor as DanRen mentioned).

This data acquisition device then connects to your PC (e.g. via USB, RS-232, Ethernet etc.) and then you use an appropriate driver (e.g. DAQmx, VISA) to read the data from the device in LabVIEW.

Does your data acquisition device have an RS-232 output, or are your 4 current sensors just wired to a DB-9 (commonly used for RS-232) connector. If it's the former, you need to provide information on your DAQ device. If it's the latter - you need a data acquisition device.

[Dennis_Knutson]

If you don't the protocol, you'll never be able to read the devices with LabVIEW or any other programming language. Why you posted here without providing any sort of detailed information on the devices (vendor, model number, etc), is something I don't understand.