digital output for NI6009

[Samsur]

Hi,

Here I attached spec sheet of SSR and pin config of NI6009. As I mentioned that SSR  GD280D90 draws only 1.5 mA at 1.6 v from a power supply and turns on. Power supply was connected to pin 3 &4 of SSR.

 Using Lab vi DAQ assistant high digital out is found between P0.0 and P0.1 of NI6009. But it is not between P0.0 and GND. I dont know why?

Do I need to add a pull up resistor in between P0.0 and +5 V (shown in fig) to make it as a source? how much should be ohms to get desired output?

Please suggest with complete solution as how I can get desired output from 6009..

Thanks

Samsur

[johnsold]

As someone suggested earlier, you need to use the pulldown capability of the 6009. Connect the SSR where Re is shown on Figure 15 and do not connect anything where RI is shown.  Pin 3 of the SSR goes to +5 V and pin 4 to P0.0.  No resistors required.

Lynn

[Samsur]

Hi Lynn,

Thanks for your support. I can get 5 V and 40 mA through P0.0 and can control one SSR. Now I need 3 independent line to control 3 SSR independently. Please suggest how I can wire them. Thanks

Samsur

[johnsold]

Samsur,

If you are getting 40 mA you are doing something wrong and may be damaging the USB-6009. The maximum rated current on a digital output line is 8.5 mA.

Connect the plus terminals of all the SSR controls (I think it was pin 3) to +5 V. Connect the negative control terminal of each to a different digital output line (P0.0, P0.1, P0.2 or any other lines you want).

Lynn

[apok]

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@Samsur wrote:

 I can get 5 V and 40 mA through P0.0 and can control one SSR.

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if that is the case.....it is highly recommended that you use a driver (ULN2803, Fet, Transistor,Opto coupler...) and like it was replied, "you may have already damaged the Daq (maximum current output 8.5mA)." 

[Samsur]

Lynn,

I measured this 40 mA current by placing a multimeter in Ameter mode in between P0.0 and +5V, while the SSR was also connected to the same.

Fig, 15 says, the load needs to be connected in between GND and P 0.0, but I connected between +5 and P0.0. And the DAQ manual says +5 V is  a power source which can power upto 200 mA. So, I get confused if the DAQ is damaged.

For independent multichannel output, I connected all SSRs +  pin to +5 V  and - pins to individual P 0.0, P 0.1 etc.. but by setting low to P0.0 and high to others does not actually change output. Is it possible that the channels became short ?

Thanks

[johnsold]

Samsur,

To measure the current the ammeter must be in series with the load.  In your case that is the SSR input. The way you measured it appears that you had the ammeter in parallel with the load which means you essentially shorted the P0.0 digital output to +5 V when it was trying to drive low (toward zero V). You may have damaged the device.

With everything (except a voltmeter or oscilloscope) disconnected from the digital ports try changing the lines from high to low and back and see if they change. If they have normal voltage levels, then the device may be OK. 

Lynn