Data Acquisition System Supports Modbus Protocols Dataforth Corporation's SCM5B isoLynx® SLX200 data acquisition system is fast, intelligent, modular, and fully isolated. As it implements industry standard Modbus RTU and TCP protocols, the SLX200 enables communication with a wide variety of existing third-party software drivers and HMI/SCADA packages. Fully certified by the Modbus-IDA organization and also compatible with OPC, 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, and complemented by Dataforth's ReDAQ™ remote data acquisition system software, the SCM5B isoLynx® SLX200 offers maximum flexibility for factory automation, process control, test and measurement, machine control, and data acquisition applications.

The communication protocol is Modbus RTU for RS-232/RS-485 or Modbus TCP for Ethernet. The SLX200's full certification ensures the device can be easily integrated onto existing Modbus networks, and most common Modbus function codes (1, 2, 3, 4, 5, 6, 15, 16, 23) are supported.
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. The system accepts single-channel digital or analog I/O modules. All I/O is channel-to-channel and channel-to-bus isolated.

One I/O controller module can operate up to 60 channels of differential analog I/O and 128 channels of digital I/O, using Dataforth's versatile SCM5B analog and SCMD digital modules. The 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 17msec. The D/A converter is also a 16-bit device and can write a maximum 60-channel configuration in 33msec.
Key features of the SCM5B isoLynx® SLX200 data acquisition system include:


Key features of the SCM5B isoLynx® SLX200 data acquisition system include:

  • Modbus RTU Support on RS-232 and RS-485
  • Modbus TCP Support (optional)
  • 1500Vrms Channel-to-Channel and Channel-to-Bus Isolation & 240Vrms Field-Side Protection
  • Fast 16-Bit A/D, D/A
  • Best I/O Selection with 650+ Different I/O Modules
  • -40°C to +85°C Industrial Operating Temperature
  • Free Software Configuration Utility
  • CSA Certified, FM Approved (Class I, Division 2, Groups A, B, C, D)
  • CE Compliant
  • Manufactured According to Regulations of RoHS Directive 2003/11/EC

The SCM5B isoLynx® SLX200 communicates on RS-232/RS-485 non-isolated serial links up to 115.2kbps or 10Mb/s Ethernet. Standard communication is RS-232/RS-485; up to 32 systems can be multidropped on the RS-485 serial link. Optional Ethernet communication boards are available and can be either factory installed or upgraded in the field.

As device configuration is performed using standard Modbus function codes, any third-party software application that supports Modbus RTU or TCP protocol can be used for configuration. Parameters are stored in non-volatile memory, so configuration only has to take place once. A free software configuration utility provided with the device makes the process easy and intuitive.
The 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, used to obtain data with highly accurate time correlation between samples, provides user-configurable scan parameters such as scan list, scan rate, and scan count. Other powerful firmware features of the SLX200 include automatic analog output refresh and configurable default output values.

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.
The highly modular design of the SCM5B isoLynx® SLX200 and the ability to keep all wiring connected to the system when accessing I/O modules ensure excellent field serviceability and easy upgrades.

Dataforth Corporation was established in 1984 and is a worldwide leader in the design and manufacture of data acquisition, signal conditioning, and data communication products for industrial and institutional markets. Dataforth products are manufactured in the USA and the Dataforth Quality Management System is ISO9001:2015 registered. Each product made by Dataforth Corporation has been manufactured according to the regulations of the RoHS Directive 2003/11/EC.

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

Original release: May 1, 2007; updated March 2009 and November 2009