# SIMPL+ Programming Language Reference

> Complete reference documentation for Crestron SIMPL+ programming language
> Version: 1.0.0
> Updated: 2026-04-16
> Base URL: https://simplplus.crestron.rocks

## Overview

SIMPL+ is a programming language for Crestron control systems. It extends SIMPL (Symbol Intensive Master Programming Language) with C-like syntax for complex logic, string manipulation, and file I/O.

## Documentation Structure

### Allowable Ranges for 2 Series Numeric Formats
- Allowable Ranges for 2 Series Numeric Formats

### Examples
- Examples

### General Information
- Comments
- Conventions Used
- Introduction
- Legal Information (Part 1)
- Legal Information (Part 2)
- Relative Path Names for Files
- Variable Names

### Language Constructs & Functions
- Arrays
- GetLastModifiedArrayIndex
- GetNumArrayCols
- GetNumArrayRows
- GetNumStructureArrayCols
- Array Operations Overview
- ResizeArray
- ResizeStructureArray
- SetArray
- Bit
- ... and 494 more

### Obsolete Functions
- System Interfacing Functions

### Operators
- Arithmetic Operators
- Bitwise Operators
- Numeric Formats
- Operator Precedence & Grouping
- Operators Overview (Part 1)
- Operators Overview (Part 2)
- Operators Overview (Part 3)
- Relational Operators
- Signed vs Unsigned Arithmetic

### Programming Environment
- Bookmarks
- Compile Output Files
- Compiler Options
- Cursor Positioning
- Edit Menu
- Edit Select All
- Edit Preferences
- Edit Preferences Text Editor Colors
- Find Next
- Insert Category
- ... and 5 more

### Revision History
- SIMPL+ Revisions
- Software Requirements

### SIMPL Plus Tutorial
- Compact Flash Functions
- CheckForDisk and WaitForNewDisk
- Reading and Writing Data
- Controlling Program Flow: Branching
- if‑else (Part 1)
- if‑else (Part 2)
- switch-case
- Controlling Program Flow: Loops
- for Loops (Part 1)
- for Loops (Part 2)
- ... and 58 more

### Task Switching
- Task Scheduling Changes and Consequences (Part 1)
- Task Scheduling Changes and Consequences (Part 2)
- Task Scheduling Changes and Consequences (Part 3)
- Task Scheduling Changes and Consequences (Part 4)
- Task Switching for 2-Series Control Systems (Part 1)
- Task Switching for 2-Series Control Systems (Part 2)
- Task Switching for 2-Series Control Systems (Part 3)
- Task Switching for X-Generation (CNX) Control Systems (Part 1)
- Task Switching for X-Generation (CNX) Control Systems (Part 2)

### What's New
- Converting from an X-Generation to a 2-Series Target
- SIMPL+ Revisions
- X-Generation Target and 2-Series Target Differences

## Quick Reference

### Data Types
- INTEGER, LONG_INTEGER (unsigned)
- SIGNED_INTEGER, SIGNED_LONG_INTEGER
- STRING (with size declaration)

### I/O Types
- DIGITAL_INPUT, DIGITAL_OUTPUT
- ANALOG_INPUT, ANALOG_OUTPUT
- STRING_INPUT, STRING_OUTPUT, BUFFER_INPUT

### Events
- PUSH, RELEASE, CHANGE (input events)
- WAIT (timed events)
- Function Main() (initialization)

### Key Functions
- MAKESTRING, PRINT, TRACE (output)
- LEFT, RIGHT, MID, FIND (string ops)
- FileOpen, FileRead, FileWrite (file I/O)

## Files

- `https://simplplus.crestron.rocks/llms.txt` - This file (quick reference)
- `https://simplplus.crestron.rocks/llms-full.txt` - Complete documentation (620 sections)
- `https://simplplus.crestron.rocks/index/chunks.jsonl` - Structured chunks for RAG
- `https://simplplus.crestron.rocks/source/` - Clean markdown source files