There are at least five different ways to provide redundancy in a data acquisition system, and combinations of these redundancy methods can create numerous hybrid systems. Fortunately, Dataforth Corporation's isoLynx® SLX200 industrial data acquisition system can be applied across all types of redundant configurations.

SLX200 data acquisition system The SLX200-30 is the dual-Ethernet model of Dataforth's isoLynx® SLX200 family. It offers two independent, 10Base-T Ethernet ports, each of which implements the industry standard Modbus TCP protocol. Simultaneous communication with both Ethernet ports is supported, and each Ethernet port supports up to four socket connections at TCP port 502. Each socket is capable of servicing up to four Modbus TCP commands at a time. In addition, users can configure each 10Base-T port with individual socket keepalive timeouts (the default is configured with a timeout of two hours).

Basic Redundancy Types

Type: Redundant: Provides For: Dataforth IsoLynx® Selection:
1 Power Supply Basic power backup SLX200-any
2 Data Path Backup data path SLX200-30
3 Network Node Path around single failed switch SLX200-30
4 Network Path around multiple failed switches SLX200-30
5 Complete System Path around failed system SLX200-30


Dataforth's isoLynx® SLX200 data acquisition system is fast, intelligent, modular, and fully isolated. It is also fully certified by the Modbus-IDA organization and compatible with OPC, thereby ensuring the SLX200 can be easily integrated onto existing Modbus networks.

The SLX200 provides superior reliability, accuracy, and isolation for a wide range of rugged high performance industrial applications. With its ability to interface with more than 650 SCM5B analog I/O modules, the isoLynx SLX200 offers maximum flexibility for factory automation, process control, test and measurement, machine control, and data acquisition applications.

In addition to the protections provided by redundancy, isoLynx SLX200 hardware and SCM5B signal conditioning modules exceed 500,000 hours MTTF (mean time to failure). The hardware is manufactured in Tucson, AZ (USA) under a certified ISO9001:2015 Quality Management System and each element exceeds Six Sigma reliability.

A free SLX configuration software utility, provided with the SLX200, can be used to configure Ethernet port communication parameters such as the IP Address and Subnet Mask.

Detailed graphic examples of the five different redundancy methods and additional information about Dataforth's SLX200-30 redundant Ethernet data acquisition system are available on the Dataforth website at http://www.dataforth.com/Dual-Ethernet.pdf.

The flexible, modular design of the SLX200 combines a 6- or 12-channel I/O Controller base system and optional 8- or 16-channel expansion backplanes, which can be either panel or DIN rail mounted.

One I/O Controller module can operate up to 60 channels of analog I/O and 128 channels of digital I/O using Dataforth's versatile SCM5B analog and SCMD digital modules. The I/O Controller contains a powerful high-speed microcontroller, A/D and D/A subsystem, communication interface, associated memory, and status LEDs. The A/D system is built around a 16-bit, successive approximation converter and can convert a maximum 60-channel configuration in 15msec. The D/A converter is also a 16-bit device and can write a maximum 60-channel configuration in 30msec.

In addition to Ethernet models, the SLX200 also offers models that implement industry standard Modbus RTU protocol for RS-232/RS-485.

Key Features of the isoLynx SLX200 Data Acquisition System:

  • Modbus TCP Support on 10Mb/s Ethernet
  • Modbus RTU Support on RS-232/RS-485 at Data Rates up to 115.2kbps
  • 240Vrms Field-Side Protection
  • Channel-to-Channel and Channel-to-Bus Isolation of 1500Vrms Analog I/O, 4000VDC Digital I/O
  • 16-Bit A/D, D/A
  • Up to 6-Pole Analog Input Filtering
  • ±0.012% Base System Accuracy, No Modules
  • ±0.005% Base System Linearity, No Modules
  • ±0.03% Module Accuracy
  • ±0.005% Module Linearity
  • I/O Selection of 650+ Different I/O Modules
  • -40°C to +85°C Industrial Operating Temperature
  • All Modules Certified to CSA, FM, CE, and ATEX Requirements
  • System CE Compliant, CSA Certified, FM Approved
  • OPC Compatible
  • Free Configuration Software
Device configuration is performed using standard Modbus function codes, allowing any third-party software application that supports Modbus RTU and/or Modbus TCP protocols to be used. As parameters are stored in non-volatile memory, initial configuration is all that is required.

The isoLynx® SLX200 supports two analog scan modes: one for general purpose signal monitoring with running average, maximum, and minimum values available for each analog input; the other, with user-configurable scan parameters such as scan list, scan rate, and scan count, used to obtain data with highly accurate time correlation between samples. Other powerful firmware features of the SLX200 include automatic analog output refresh, which ensures signals remain solid at the levels where they were initially set, and configurable default output values that ensure output signals are set at safe levels when unexpected power outages or brown-outs occur. Power-on self-test results can be obtained visually by glancing at a status LED or programmatically by reading the appropriate register on the device. A section of memory is set aside for general purpose user data, some of which is stored in non-volatile memory.

The ability to select from Dataforth's 650+ standard and custom single-channel SCM5B analog I/O modules means the SLX200 can interface to a broad spectrum of analog signals, including millivolt, volt, milliamp, amp, linearized and non-linearized thermocouple, RTD, potentiometer, slidewire, strain gage, AC-to-true-RMS output, frequency, 2-wire transmitter, and transducers requiring DC excitation. All Dataforth SCM5B standard and custom modules provide superior specifications, including ±0.03% accuracy, ±0.005% linearity, 1500Vrms isolation, and 240VAC input protection.

Operation and storage temperature for the isoLynx SLX200 is -40°C to +85°C, and relative humidity range is zero to 95% non-condensing. Power requirement is +5VDC, 2.5W base system with no modules installed. The system is designed to meet the requirements of EN61000-6-4 (radiated/ conducted emissions) and EN61000-6-2 (ESD/RF/EFT immunity).

Dataforth Corporation was established in 1984 and is a worldwide leader in the design and manufacture of signal conditioning, data acquisition, and data communication products for industrial and institutional markets.

For additional information, call 800-444-7644 toll-free, or e-mail sales@dataforth.com.

Original release: May, 2008