I/O TEMPLATES

An ONSPEC I/O Template, or I/O Driver, is a software input-output interface between the ONSPEC real-time database and the field instruments.

Real-time data is acquired from the instruments through the I/O Template by ONSPEC to update its real -time database. On the other hand, data from the computer can be sent to the instruments through the I/O Template for control purposes.

The data communication between the instrument and computer is based on a communication protocol, which is actually a pre-designed data string definition. Since each instrument may use its own communication protocol, and have its own memory map and addressing scheme, specially developed ONSPEC I/O template software is required for each type of instrument.

Each I/O template may have its own operating procedures. For details in this area, consult the individual User Guide for the I/O Template. However, most I/O templates are designed to use command lines that the users will configure to specify

  • Whether the data is to be input or output
     
  • How often the data should be sampled
     
  • Where the data is in the instrument
     
  • Where the data is kept in the ONSPEC data tables
     
  • What data conversion, if any, is to be used
     

These command lines are saved in a configuration file for the I/O template.

The communication speed of the I/O template may vary based on the following issues:

  • The communication protocol used
     
  • The speed of the computer CPU, RAM, etc.
     
  • The number of the programs running at the same time in the computer
     
  • The number of the command lines to be executed
     
  • The execution frequency of the command lines
     
  • The data packaging scheme used (such as block read), etc.
     

ONSPEC I/O templates are designed to include the following features and specifications depending on the individual instrument:

  • Reliability
     
  • Serial communication standard: RS-232, RS-422, RS-485
     
  • High speed network communication (Data-Hiway Plus, Modbus Plus, Ethernet, Siemens H1, etc.)
     
  • Direct Memory Access (DMA) (for most I/O boards)
     
  • Time, batch, or event based data polling or sending
     
  • Historical Database
     
  • Automatic startup and shutdown
     
  • Sleeping mode for saving CPU time or redundancy backup
     
  • Easy configuration and maintenance
     
  • Multiple I/O Templates (same or different kind) can run at the same time
     
  • Multiple serial port support (using boards or DEC Terminal Server)
     
  • Use of special data processing technique (such as look first) for high efficiency of data communication
     
  • Based on the software coding standards defined and used in ONSPEC Technology Pack
     
  • Multi-platform or operating system support, etc.
     

Note: Limitations in an ONSPEC I/O template are usually the result of the limitations in the field instruments.

The ONSPEC Family of Automation Software includes a number of I/O templates that support most name brand instruments on the market. These I/O templates include, but are not limited to, the following:

  • Data Acquisition Devices or I/O Boards: ACIC, Action, Adventech, Analog Device, Burr-Brown, Contec, L&N, Opto 22, Solartron, etc.
     
  • Programmable Logic Controllers: Allen-Bradley, GE, Koyo, Modicon, Mitsubishi, Omron, Samsung, Siemens, Square D, Texas Instruments, Westinghouse, etc.
     
  • Loop Controllers: Eurotherm, Fisher, Fischer & Porter, Foxboro, Fuji, Honeywell, Moore Products, Siemens, Turnbull, Toshiba, etc.
     
  • Distributed Control Systems: Bailey, Computer Products, Fisher, Foxboro, Honeywell, Leeds & Northrup, Measurex, Reliance, Siemens, Yokogawa, etc.
     
  • Other Instruments: Fluke, Rosemount, Mitutiyo, etc
     


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