Alta has designed their interface products to utilize an industry-standard IRIG-B time source, but we do not utilize that time source as the “master” for all of our internal timing. Instead, we use our internal 50MHz clock as we normally do, but in the presence of an IRIG-B input, we latch BOTH the IRIG-B time and our internal time once per second, and store deltas values between these two so that the user can add those deltas to Alta 1553 CDP (Alta Common Data Packet) time stamps and Alta ARINC RxP (Receive Packet) time stamps to obtain relevant IRIG-B time stamps in CDP or RxP data. See the IRIG-B discussion in the AltaAPI Users Manual.
