ErrStat
ErrStat(sts != SMS_SC_WRITE_START, "%s: wstart", __func__);
ErrStat(sts != SMS_SC_WRITE_NEXT, "%s: write", __func__);
ErrStat(sts != SMS_SC_READ_START, "%s: rstart", __func__);
ErrStat(sts != SMS_SC_READ_END, "%s: rend", __func__);