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6.5. Using “Wait For” Event
6.5.1.
The “wait” function is a powerful tool for pausing a program until a particular process variable
reaches a predefined set point. This differs from the guaranteed soak function by being a single
shot monitor. With the guaranteed soak, the process variable is monitored throughout the whole
step. If the process exceeds the upper or lower soak band, the program will pause until the process
returns to within the band. The wait for function puts the program in hold and “waits for” the
process to exceed a particular value that is set for the step. Once the process reaches this set
point value, the program will resume.
6.5.2.
A program can also be set to wait for a digital input. This allows any of the eight optional digital
inputs to be selected. When the EZT-570S reaches the step, it will wait for the input to change
state before continuing the step.
6.5.3.
To enable a wait condition in a step, first press the ‘Wait’ button above the event list view on the
Program Entry screen. This will display the list of available wait selections. Select the input to wait
for, and if a process variable is selected (Loop or monitor input) enter the set point for the wait.
This is the set point that the process variable must reach in order for the step to continue.
The set point entry for a wait step is critical for the “wait for” loop or monitor to operate correctly.
During the wait state, the selected process input must arrive at or cross the set point (Wait SP) in
order for the program to resume operation.
6.5.4.
The monitor input and digital input selections are only available if the option is available on your
chamber. When using a digital input as a wait for selection, the digital input must be configured as
a “wait input”. If it is not configured as a “wait input”, the program will ignore the wait for selection
and continue through the step. See EZT Manual for more information.
