Digital I/O

cancel
Showing results for 
Search instead for 
Did you mean: 

NI-USB 6008 Digital Output for SSR control

Hello I'm having a bit of an issue with controlling a SSR with my NI-USB 6008. I'm trying to control a G3NE-205T-US-DC5 Control SSR with the Digital Output from the USB 6008 which as far as I can tell should have no problems providing the 5VDC and the SSR needs 5mA of Input current which seems to be pushing the capabilities of the Analog Outputs on the 6008 so I've instead tried to turn to the Digital Outputs. Connecting one of the outputs and GND directly to the SSR terminal 3 and 4 unfortunately only gives 1.2V on High and connecting and ammeter shows it giving .8mA, im not entirely sure the reason for this so I've attempted two wiring configurations from the 6008 user guide (seen below). In the first configuration I can't seem to get any pull up resistor value to work correctly, and in the second configuration (#1 in the second picture) I've also tried a few different resistor values in series but to no avail, the closest I got was having no resistor in series and getting 4.31 V and apparently 15mA through the ammeter (which as far as I can tell should have been enough to trigger the SSR and is somehow more mA then the 6008 can output. As a final note hooking the 5V and GND from the 6008 to terminals 3 and 4 of the SSR works as expected turning on the SSR. I think at this point I may just be missing something extremely obvious but any help is appreciated.

AlexiaC_0-1653091969297.png

AlexiaC_1-1653092007325.png

 

 

0 Kudos
Message 1 of 4
(977 Views)

Tried a TTL buffer between the 6008 and the SSR?

0 Kudos
Message 2 of 4
(848 Views)

configure output drive type to ACTIVE DRIVE

To set the Output Drive Type of a Digital Channel, use the DAQmx Channel Property Node. The property is found under Digital Output>>Output Drive Type.

0 Kudos
Message 3 of 4
(400 Views)

During active driving a high, the output can only provide up to 3.5V at 8.5mA load as specified in the datasheet.

 

santo_13_0-1698027664338.png

 

Instead what you can do is to use the output in a configuration where you connect the Pin3 of SSR to 5V pin of 6008 and the pin 4 of SSR to the digital output line. This way, you tend to get up to 4.2V across the SSR at 8.5mA.

 

 

Based on your SSR specs, it looks like 6008 is not equipped to power it properly, with a worst case input impedance of 200 ohms (-20%), your SSR requires at least 20mA at 4V.

 

santo_13_1-1698027914333.png

 

Santhosh
Soliton Technologies

New to the forum? Please read community guidelines and how to ask smart questions

Only two ways to appreciate someone who spent their free time to reply/answer your question - give them Kudos or mark their reply as the answer/solution.

Finding it hard to source NI hardware? Try NI Trading Post
0 Kudos
Message 4 of 4
(393 Views)