You are here: Building the Model: General Elements > Tanks > Basic Concepts > Tank Downtimes
For Tanks, you must define downtimes and shifts in a special way. First, you may define only clock downtimes for tanks. Second, when defining a clock downtime for a tank, use the Tank_GoDown subroutine (Tank_GoDown) in the Downtime Logic field instead of just a WAIT statement. This sets the state of the tank to Tank_Down and gathers the appropriate statistics. Third, when defining a shift for a tank, you should call the Tank_GoDownSched subroutine in the off-shift logic using the DTLeft() function as the time parameter. A SKIP statement should follow this function as shown next.
SKIP example
Tank_GoDownSched (<TankID>, DTLeft())
SKIP
ProModel temporarily suspends tank flow while a tank is down or off shift.