# Operators

Aim

To combine actions, conditions and sub-rules in various ways.

examples (Operators are highlighted in italics)

▪When at least one of the two conditions A and B is met, then do …

This is an example of conditions combined by an operator of the “Any” type (OR logic).

▪When two conditions are met at the same time, then do …

This is an example of conditions combined by an operator of the “All” type (AND logic).

▪When at least/at most/exactly 4 of 8 conditions are met, then do …

This is an example of conditions combined by an operator of the “N of All” type.

To combine conditions/actions/rules:

1.Define the conditions/actions/rules that you want to combine. Place them in your Trial Control sequence as parallel branches. The connecting arrows must originate from the condition/action that precedes the combination of elements you want to define.

2.In the Components pane under Structures, double-click Operator or click the button next to it.

3.Under Name, enter the Operator name or accept the default name Operator (n), where n is a progressive number.

4.Under Operator triggers when, select the option that applies:

▪Any (at least one) of the inputs is 'true'.

▪All inputs are simultaneously 'true'.

▪N of All inputs are simultaneously 'true'. Specify how many inputs N must be 'true': = (exactly equal to), ≠ (not equal to), >= (at least), <= (a maximum of), etc.

Where an input being 'true' means a condition being met, an action carried out, or a sub-rule finished.

5.Enter a Comment (optional) to describe this operator, and click OK.

6.A new Operator box appears in the Trial Control. Place the box right of the elements defined in step 1, and connect each element (or ending element, in the case of a sequence) to the operator.

7.Connect the operator to the next element that should be activated.

Notes

▪Instead of using multiple condition boxes, you can also combine conditions with Multi condition. For details, see the EthoVision XT 19 - Trial and Hardware Control - Reference Manual.

▪If the Add an operator window appears, it means that there is at least one operator of the same type in your experiment. For more information, see Re-use trial control elements.

▪Names of operators must be unique in your experiment. You cannot define two operators with the same Operator name.

▪An Operator can also have just one input box. In that case the operator is of no use, because control passes immediately to the next box as soon as the input condition becomes true or the input action is carried out. EthoVision informs you about this.