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In process controller software, click on the "Rules & States" tab and create an OFF state. This state is an important state in case you wish to shut down the experiment at any point.
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Step Two: Create the Rule to Switch State
Process Controller requires rules in order to switch to a different state (mode of operation). In creating a rule to switch between states, you need to determine what state you wish to switch to next, and the rule for switching that state.
Rules are conditional if statements for requirements to change state. You can add more than one rule for each state. Each rule you add will act as AND statements. The computer will satisfy the first rule then satisfy the conditions of the second rule before switching states.
Adding additional conditional statements in the same rule act as OR statements. If any of the conditions achieved on the rule list are met, then the computer will proceed to the next state.
The OFF state is a state that we utilize when we want everything shut down. When we shut everything down, we do not want it to then swith to a different state (mode of operation) such as adding chemical to a stock tank. Therefore we should set the state to switch to next as OFF state. The rule here is trivial, but we can set the rule that if time elapsed in the current statement is greater than OFF (a value of zero) then we will switch to the OFF state. Sketch this rule out if it seems confusing.
Step Three: Add More States
The next step is to add two new states: Add Chemical and Settle. First, click add new state and name the state "Add Chemical." For this state, we need a rule. There are many rules we could create, but for simplicity's sake, let's say that if the time in the Add Chemical state exceeds 1000 s that we should switch to "Settle."
In order to make this rule we first have to create a new state "Settle." Do so, adding the state after Add Chemical.
You can see that in the figure above that the next state to proceed to is set to OFF. Set this instead to Settle.
Step Four: Create Set Point for Rule
Next we need to create a set point so that the computer has a value for the 1000 s time interval which it will spend in the Add Chemical State. Click on set points and click Add Set Point after the last set point you just added. Title the set point "Time for Add Chemical" and enter a value of 1000 (as the time in Process Controller is measured in seconds).
Step Five: Edit State to Correspond with Stamp Box Controls
In the Rules and States tab, click on States.
