snap ethernet-based i/o units protocols and programming guide

Chapter 1
Introduction
CHAPTER 1
Welcome to SNAP Ethernet-Based I/O
Opto 22’s SNAP Ethernet-based I/O units offer you a uniquely versatile and powerful
input/output (I/O) system for local and remote monitoring, industrial control, and data
acquisition. Based on the Internet Protocol (IP), these systems offer flexibility in both directions:
flexibility in the physical network on which they sit and flexibility in the software applications
with which they interface.
Ethernet-based I/O units can be placed on a wired or wireless LAN Ethernet network, a
cellular wireless network, or with a modem over PPP (point-to-point protocol).
Ethernet-based I/O units can send data to and receive data from a wide variety of software
applications, including human-machine interfaces (HMIs); manufacturing resource planning
(MRP), enterprise management, and other enterprise systems; databases; email systems;
OPC client software; Modbus/TCP software and hardware; and custom applications; as
well as Opto 22’s own control and HMI software.
Hardware
Each SNAP Ethernet-based I/O unit consists of a processor we call the brain, a mounting rack,
and standard Opto 22 SNAP analog, digital, and serial input/output modules that connect to the
equipment and devices you need to monitor, control, or acquire data from. I/O units come in three
categories.
SNAP Simple I/O is the low-cost, high-quality solution for simple
monitoring, control, and data acquisition using a wired Ethernet
network. SNAP Simple I/O is ideal for high-density commercial and
industrial applications. It offers simple digital and serial capabilities,
plus full analog features, all on the same 16-module rack. For a control
system, use SNAP Simple I/O with a SNAP-LCE industrial controller or
SNAP Ultimate I/O .
SNAP Ethernet-Based I/O Units Protocols and Programming Guide 1