Installation guide

The following table shows how changing the physical switch position affects the Logic In ports and

the corresponding Selector control:

Switch Position

Logic In Port

Selector Control

4 3 2 1

1 High High High Low Selection 1

2 High High Low High Selection 2

3 High Low High High Selection 3

4 Low High High High Selection 4

A set of DR4 Logic In ports configured as a one-of selector is not a read-only control because the ports

only sense when the switch closures occur – that is when the port input signal goes from logic high to

logic low as described above. This means that you can link the corresponding selector control in the

Processing Workspace to other selector controls and each of the participants can change the selection

value. It also means that this approach works best with a physical selector that uses a set of momentary

normally open push button switches.

While the port is not read-only, other selectors can change and follow each other, but the physical

switch cannot follow – thus the switch may not always show the proper indication. All selectors return

to the physical switch setting the next time the physical switch is changed.

Binary Selector

CHAPTER 2: Introduction to the HAL System