It certainly helps that you can connect Soft-I/O to the light tower without any terminal blocks or elaborate wiring.  You simply hook the wires from the light tower to pins on Soft-I/O and then configure Soft-I/O.

Light Tower Wizard

The real power of Soft-I/O is that it contains a Soft-Device simply called "light tower".  When you click on the "create Light Tower Soft-Device" you are led by a wizard through the process of configuring a pretty complex state machine that will handle the Light Tower.

Let's assume that you want the light tower to have its green light on solid during "normal operation".  When the tool is approaching the time for the tool operator to add new product, the orange light will begin to flash slowly--perhaps at 1 Hz.  As the time to service the tool approaches, you want the light to flash progressively faster.  When the time arrives, you want the orange light on solid.

Acknowledge

When the operator reaches the tool, you want the operator to press the "acknowledge" pushbutton.  At this point, the orange light should go off and the green light should flash slowly indicating that the tool is being serviced.  When the tool has been loaded, the green light should go back to solid.

Error Handling

In the event that the tool experiences an error, the red light should come on and flash slowly.  When the technician arrives to work on the tool and presses the "acknowledge" pushbutton, you want the red light to go solid.  When the tool is back on line, you want the red light to turn off and the green light to come on solid.

In Practice

We have talked to semiconductor tool software engineers who have told us that they spend uncountable hours working on software to drive their light towers.  It seems as if each of their end user customers has a slightly different requirement for their light towers.  With Soft-I/O, changing the configurations is simple.  There is never any programming.  When the configuration is finished, it is uploaded to a PC and saved as part of the tool software configuration files.

We have been told that Soft-I/O is the best light tower controller that they have used.  It's just one of many things that make Soft-I/O the magic box.