At about 9:03 PDT, there was a timing error detected by the DACs on h1sush2b, which resulted in all outputs being set to 0.  The only remedy is to restart the IOP model, so I killed h1susim, restarted h1iopsush2b, then started h1susim again.  This has cleared the DAC error.  I burt restored to 8:00 PDT.