laddercodec

Binary codec for AutomationDirect CLICK PLC ladder clipboard format.

laddercodec encodes and decodes the native clipboard binary used by CLICK Programming Software (v2.60–v3.80). It's the codec layer that powers clicknick.

What it does

• Encode — CSV rung descriptions → clipboard binary, ready to paste into Click
• Decode clipboard — clipboard binary → structured data (contacts, coils, wires, comments)
• Decode program — Click program files (Scr*.tmp) → full program with all rungs
• Round-trip — decode(encode(data)) == data for all supported instruction types

Who it's for

• clicknick developers — this is the codec clicknick uses under the hood
• Reverse engineers — the internals section documents the binary format byte-by-byte
• Tool builders — anyone generating or consuming Click clipboard data programmatically

Quick example

from laddercodec import read_csv, encode, decode

# CSV → structured data → binary
rungs = read_csv("my_rung.csv")
binary = encode(rungs[0])

# Binary → structured data
decoded = decode(binary)
assert decoded.logical_rows == rungs[0].logical_rows

Current status

Beta. All standard Click instruction types are supported — contacts, coils, timers, counters, copy/fill/pack/unpack, math, shift registers, drums, search, flow control (call/return/end/for/next), and Modbus send/receive. See supported instructions for the full list.

Program file decoding (decode_program) is alpha — functional but not yet extensively tested.

Guide overview

Section	What's in it
Getting Started	Install and encode your first rung
Guides	Encoding, decoding, CSV format, adding new instruction types
Internals	Binary format spec, wire rendering rules, instruction blob structure
API Reference	Auto-generated from docstrings