Meanwhile, back in California, John Reykjalin was making progress on fixing two processing boards from the CW detectors. John designed and built these boards in 1992. Working with documentation he wrote more than seven years ago, the boards were starting to work again. So, it was time for more system tests. By evening we had another curious error.
Intermittent problems are the hardest to track down.
Wednesday morning arrived with several email replies waiting for us. All pointed to the same conclusion. One of the MCSAs was not getting the time signal from the observatory. Our susbsystems recieve a one pulse per second electronic signal that is tied to the observatory master clock. We also broadcast the time of day once per second over our internal network so that the subsystems know what each of the pulses means.