NOTE: Although still fully supported and in production, the SNAP Simple brain is not recommended for new development. We recommend the SNAP-PAC-EB2 brain instead.

Opto 22 SNAP Simple I/O™ is a low-cost solution that offers Ethernet/TCP communications as well as analog, simple digital, and serial capability on the same mounting rack. Used for high-density commercial and industrial applications and for remote monitoring applications with high I/O point counts, a SNAP Simple I/O unit consists of a SNAP-ENET-S64 brain mounted on a SNAP M-series rack with standard SNAP I/O™ analog, digital, and serial modules.

This guide is for programmers who are writing custom applications to communicate with Opto 22 memory-mapped devices. These devices include SNAP PAC controllers and SNAP PAC EB and SB brains; G4EB2 brains; SNAP Ultimate, SNAP Ethernet, and SNAP Simple I/O; E1 and E2 brain boards, and SNAP-LCE controllers.

The guide describes how to use the IEEE 1394-based OptoMMP memory-mapped protocol for programming. The guide also contains the complete memory map for all Opto 22 memory-mapped devices.

NOTE: This guide replaced previous individual programming guides for SNAP Ultimate I/O (form #1312) and SNAP Ethernet I/O (form #1227). This document was formerly called the "SNAP Ethernet-Based I/O Units Protocols and Programming Guide."

This document shows you how to set up communication between Ethernet-based Modbus systems (using Modbus/TCP) and the SNAP PAC System. In addition to the SNAP PAC System (SNAP PAC S-series and R-series controllers and SNAP PAC brains), the guide also covers Modbus/TCP communication with older Opto 22 Ethernet-based devices, including SNAP Ethernet, SNAP Simple, and SNAP Ultimate I/O; and E1 and E2 brain boards.

This README file lists revision changes made to the firmware used in SNAP PAC family controllers before Version 8.0a, the SNAP-LCE controller, and SNAP Ultimate, Ethernet, and Simple brains.

This technical note shows you how to set offset and gain for Opto 22 analog input modules.