Check on 2nd to last cycle for signal down

src/fe/sync21pps.c

@@ -178,16 +178,17 @@ int sync21pps_check( one_pps_sync_t* p1pps, adcInfo_t* padcinfo, int cycle_64k_H
         p1pps->last_cycle_high = 0;
     }
 
-    //On last cycle, we expect one of each transition
-    //and to be in the low state
-    if ( cycle_64k_Hz == MODEL_RATE_HZ ) {
+    //On 2nd to last cycle, we expect to have transitioned 
+    //in the allowed cycles and to be in the low state
+    if ( cycle_64k_Hz == (MODEL_RATE_HZ/UNDERSAMPLE) - 2) {
 
         if( p1pps->transition_high_cycle > MAX_CYCLE_FOR_1PPS_TO_BE_HIGH ||
             p1pps->transition_high_cycle < 0 || 
             p1pps->last_cycle_high == 1) {
-                RTSLOG_ERROR("PPS Tracking error, transition_high_cycle: %d, last_cycle_high: %d\n", 
+                RTSLOG_DEBUG("PPS Tracking error, transition_high_cycle: %d, last_cycle_high: %d, PPS chan val: %d\n", 
                              p1pps->transition_high_cycle,
-                             p1pps->last_cycle_high);
+                             p1pps->last_cycle_high,
+                             p1pps->value);
                 return -1;
             }