Sensoray 2518 - Manual (Page 5)

Sensoray Model 2518/2519 Ethernet Smart A/D™ 2 Introduction
Chapter 2: Introduction
2.1 Functional Description
Sensoray Smart A/D™ models 2518 and 2519 directly
interface eight (model 2518) or sixteen (model 2519)
process sensors to a 10BASE-T Ethernet network.
These models are members of Sensoray’s Ethernet I/O
product family. Models 2518 and 2519 function as I/O
Servers in a client-server network model. As many as
four clients may share access to a single Ethernet Smart
A/D™ server.
Models 2518 and 2519 are modular assemblies that
consist of one or two model 518 Smart A/D boards
mounted onto a model 2509 Ethernet base unit.
Figure 1: Model 2518 8-channel Ethernet Smart A/D™
2.1.1 Ethernet Base Unit
The model 2509 Ethernet base unit is a DIN-mountable
circuit board that combines five functional elements:
DC-DC converter, intelligent network interface, PC/104
interface, field wiring terminations and optional DIN rail
mounting system.
The on-board DC-DC converter accepts any input
voltage from 12 to 24V AC/DC and produces all internal
supply voltages required by the unit.
A high performance, dedicated network processor is
coupled with an optimized TCP/IP stack. This powerful
combination simplifies software development and
accelerates application performance on virtually any
Ethernet-capable client.
Implemented TCP/IP protocols include IP as a
foundation for other network layers, UDP for command
and acquisition, ICMP for diagnostics, and ARP for
network address resolution.
Model 2509 provides a standard PC/104 bus connector
and an electrical subset of the PC/104 bus. This PC/104
interface, along with the on-board DC-DC converter, is
optimized for supporting a stack of one or two model 518
Smart A/D™ boards.
Integral screw terminals are provided for connecting the
Smart A/D™ sensor channels to external sensor field
wiring. These robust, pluggable screw terminal blocks
simplify installation and enhance maintainability.
The circuit board can be rigidly supported by an optional
DIN mounting frame that enables virtually instant
snap-on installation onto standard DIN mounting rails.
2.1.2 Smart A/D™ Daughter Boards
Sensoray’s model 518 Smart A/D™ is a standard PC/104
compatible board that interfaces eight process sensors to
any PC/104 bus.
Each of eight sensor channels may be independently
configured, via software, to accept thermocouples,
RTD’s, strain gages, thermistors, resistors, 4-to-20 mA
current loops, or DC voltage inputs.
Pulsed excitation is provided for passive sensors, such as
thermistors, resistors, RTD’s, and strain gages. Pulsed
excitation minimizes sensor self-heating effects and
helps to reduce system power consumption.
An embedded microcomputer continuously scans the
sensor channels. As each channel is scanned, its sensor is
excited, digitized, linearized, converted to engineering
units appropriate for the sensor type, and stored in
on-board memory. The newest sensor data from all
channels are always available for instant access.
2.1.3 Software
Comprehensive support software is supplied with models
2518 and 2519. The SDK includes:
q A fully documented DLL which, when used with any
standard Windows socket, provides straightforward
access to all Smart A/D™ functions.
q
Numerous Visual Basic programming examples to
help jump-start application development.