For those who need 24V output from 5V digital I/O slots of any NI product

[Giridhar_Rajan]

Here is a solution for a very common problem faced by the industry. Generally with PC based cards, we get an output of 5V, but all our industrial relays and other devices work on 24V. So, we need to obtain a 24V output when there is a 5V at the digital output of the card and 0V when there is a 0V at the digital output of the card. The first thing that comes into our mind is about the isolation between 5V and 24V. For this we can use the IC H11G2 (optocoupler). Now, this is not enough. The IC should be able to drive an industrial relay. For this, we have to use a current driver (power transistor). Transistor TIP125 goes well and can be connected at the output of the H11G2 to give the required current drive. Although this circuit has been tested by me, but I'm not responsible for any kind of damage to your hardware. Good luck.

Regards,

Giridhar Rajan

Automation Engineer

Cruiser Controls

Mumbai, India

[Jochen]

Giridhar,

thank you for sharing this information with the community. Additionally NI provides a lot of Digital I/O products that provide a complete industrial feature set (e. g. watchdog, selectable powerup-states, change detection, programmable input filters, optical isolation and industrial certification). Here is a good source of information about these features and products.
SCC and 5B modules provide off-the-shelf solutions for digital signal conditioning for almost any NI product with digital I/Os

Jochen Klier
National Instruments Germany

[AnalogKid2DigitalMan]

Off the shelf solid state relays and photomos devices work well too. Just be cautious of any logic inversion if present.

[Giridhar_Rajan]

Great information, Jochen and AnalogKid2DigitalMan. Now this thread becomes the complete solutions page for those people with this typical problem of 5V and 24V.

Regards,

Giridhar Rajan

Automation Engineer

Cruiser Controls

Mumbai, India