J

I need to calculate the sun position using ladder logic programming. It will be used in a greenhouse environment. I'm using a Koyo DL250 PLC.

The limited floating point operations on the PLC makes it hard. I'm considering calculating angles by interpolating values from a data table. But an equation would be much much nicer. Low precision is ok (within 20 degrees or so).

My main problems are:

* Comparison of float values is not available

* arctan, arccos and arcsin is not available (i've implemented sin and cos using taylor approximations)

* Square root is not available

I would appreciate any help!

// Jonatan Magnusson