# 4D_ViSi hash command – MultiTrack+ only!
The 4D_ViSi hash command gives you a very easy way of programming a SPLat EC1 board to interact with touch screen displays from 4D Systems that have been set up using 4D’s ViSi-Genie programming environment. This gives you an opportunity to match a superior hobby level controller with a cheap display.
| This is not a professional grade solution. We do not endorse the graphics products for professional use. The EC1 is designed as an inexpensive way to explore the advanced features of SPLat, such as built in multitasking and 24/7/365 program reliability. For a professional touch screen and control solution, something you can embed in your product and feel confident it will just work, look at our HMI430 controller with inbuilt touch screen. |
| To understand this material you need to be thoroughly familiar with how the 4D ViSi-Genie system works. Please study 4D Systems’ documentation. |
The programming model for ViSi-Genie is based on having several “forms” (screen layouts) that can each contain one or more “objects”. Objects are things like gauges and buttons. You design your form layouts, and specify the properties of the objects, using the ViSi-Genie programming environment.
The SPLat can interact with forms and objects via hash functions.
- Objects can be sent data from the SPLat, for example the position of a gauge or the on/off value of an LED indicator.
- Objects can also report events back to the SPLat, for example the press of a graphical button or a change in the setting of a graphical slider bar.
- The display can be sent commands from the SPLat to display a different form (screen layout) or alter its contrast setting.
Can only be used in a MultiTrack+ task. It cannot be adapted to work in our 8-bit controllers such as SL100 or CC18.