For max reps at each station:
Tabata sandbag hold (100): full time across all intervals
Tabata sit-ups: 64 (held 8 reps per round)
Tabata pushups (hand release): 56 (held 7 reps per round)
Tabata assault bike (cals): 47

The tabata interval is 20 seconds of work followed by 10 seconds of rest for eight intervals. There is no rest between stations.