40. I am using a BrandX receiver. I am never able to get OPUS to process my rinex files. I don't know if it is the data itself, the BrandX rinex converter, the receivers or what.
Check the rinex file to see if the data in the C1 and the P2 columns contain the same value. They should not be equivalent. The OPUS programs don't know how to handle this, so you should change the label P2 to T2 (T2 has no meaning, so OPUS ignores it), and add a comment line to the header stating what you did and why. This is how it should look (spacing not to scale):
4 L1 C1 L2 T2 # / TYPES OF OBSERV 4 L1 C1 L2 P2 (original designation) COMMENT C1 and P2 fields contain the same values COMMENT