IRIG-B Decoding on cRIO

[Lauren_MSI]

I’m looking for a decoder for IRIG-B125. I have found the B000 version as well as some old posts, but I haven’t found what I’m looking for. Just wondering if anyone has a solution or driver for this.

I am using a cRIO-9035 and I have an NI 9223 AI module to read the signal. I am using LabVIEW 2016 32-bit on Windows 7 (with FPGA and Real Time modules). FPGA code would be easiest I think, but I could also use a third party driver that works on the Linux OS?

Thanks!

[luda.mattski]

Hi Lauren_MSI,

As far as I know, we don't have any examples that explicitly support IRIG-B125.  There is the example you referenced earlier, and also the following example, which is does the same thing but packages everything into a project rather than just a bunch of VIs as in the B000 example:  https://decibel.ni.com/content/docs/DOC-8062

It may be easier to implement time-based synchronization using another protocol - I don't know if you're stuck using IRIG-B125, but you could look into 1588 or even Ethernet sync, as described in the following post:  https://forums.ni.com/t5/Real-Time-Measurement-and/IRIG-B-with-NI-9467/td-p/3220012/page/1.  Also, you'll need a digital module to implement IRIG-B rather than the 9223 AI module.  

[Lauren_MSI]

Unfortunately we are tied to IRIG by external requirements. There are 3rd party hardware options that I’m looking into to translate the IRIG signal and then possibly sync over another method, such as Ethernet. I was just hoping there was a simpler way to do it (cRIO or Linux drivers).
As far as digital vs analog, for some of the variants of IRIG-B (i.e. the 000) use digital (square wave pulse), but for the B125 variant it is amplitude modulated (sine wave). I don’t know the details of the algorithm for decoding, but I’m curious why you say I need a digital module.

[luda.mattski]

As far as I know, we don't have anything code that has out-of-the-box functionality to decode B125, so some third-party intermediary may be your best bet (unless you want to try and write some code that manually unpacks the signal).  

You're correct about needing an analog module - all the flavors of IRIG-B that I've used have been digital protocols, so I got a little confused.  IRIG is the first standard communication protocol that I have run across with both analog and digital variants.  

[Vincent_Carpentier]

HI Lauren_MSI,

I know this is an old thread but could you by any chance give some idea onto how you solve your problem?

We have a similar issue but in our case, we need to support both AM and DC versions of IRIG-B... Not on the cRIO platform but with a PCIe FPGA board from NI.

Thanks,

Vincent

[BaraniRam]

IRIG-B is not working with NI-9402 module.Can you list the steps to obtain the values from IRIG-B using 9402 digital module