directnet.h File Reference

AutomationDirect / Koyo DirectNET serial frame codec (DETWS_ENABLE_DIRECTNET). More...

#include "ServerConfig.h"
#include <stddef.h>
#include <stdint.h>

Go to the source code of this file.

Detailed Description

AutomationDirect / Koyo DirectNET serial frame codec (DETWS_ENABLE_DIRECTNET).

DirectNET is the AutomationDirect (Koyo) DirectLOGIC-PLC master-slave serial protocol for reading and writing V-memory. A transaction is a control-char-delimited frame with an LRC checksum. This builds the two framed messages the master sends:

• Header/enquiry: SOH [slave-hex][type][addr-hex 4][blocks-hex 2] ETB [LRC] - the request that announces a read/write of N data blocks at a V-memory address.
• Data frame: STX [data...] ETX [LRC] - the payload block.

The LRC is the longitudinal XOR of the framed bytes (between the start control char and the LRC, inclusive of the terminating ETB/ETX). This provides the framing + LRC + the ASCII-hex field helpers; the UART transport + the ACK/NAK handshake sequencing are the device step. Pure, zero heap, host-testable.

Definition in file directnet.h.