Serial communications is thought of as simple and is lucky to be thought of at all! It is generally forgotten about until the end of an installation. In fact it is usually quite tiresome in practice and can seriously hamper and delay project milestones.

The simplest ideas are often the best and RS232 using just Tx/RX and GND offers by far the simplest and easiest way to fault find a communications transmission medium.

The most commonly used protocols such as Siemens 3964R and Modbus RTU are well established sitting on RS232 links. The big problem comes with distance. It is not possible to safely go over any distance beyond around 15M with RS232. In addition, if you are operating in any sort of noisy enviroment then you are going to suffer problems. At this stage most people move to RS422 or RS485.

Whilst this is perfectly reasonable, it is then not possible to easily configure and fault find when dealing in the real world with a PLC and DCS that are not 'talking'.

Absolute Control has developed, together with Cove Enterprises, the RS232 Fibre Driver for exactly these situations. There are other drivers on the market but our devices have been designed to overcome many of the draw backs of the other units.

• The problems usually associated with other drivers are:
  • Not DIN rail mountable.
  • Require a 220Vac supply and transformer.
  • Have a jack lead power connection which fails or falls out. ·
  • ST/SM connectors are mounted to PCBs internally and so invariably come loose and break.
  • Have internal jumper settings for optical power requiring careful and time consuming setting up.
  • Internal jumper settings for filters.
  • Large DCE/DTE switches which are invariably accidentally knocked when anyone enters the cabinet thus bringing down the link without anyone realising why.

   

• To eliminate these difficulties we have designed a new unit which does not suffer from the disadvantages listed above and also has a number of additional advantages.:

• Power LED.
• DIN Rail Mountable.
• 24Vdc or ac powered via a terminal strip.
• Can run upto 30 Vdc or ac and down to 10V dc or ac making the unit very flexible.
• Robust ST/SM connectors mounted externally to the case.
• Choice of RS232 connector (male or female and 9 pin, 15 pin or 25 pin)
• Reassessed DTE/DCE switch preventing accidental switching.
• No internal jumper settings. Hence simple to set up. Units work over distance of 1M - 5 km.
• Baud rates from 4,800 - 57K The units now have separate Tx and Rx LEDs to provide further comfort when setting up and running.

These units are available at one week delivery. For further information click below to e-mail now.

All work undertaken follows a life-cycle approach and coupled with the necessary documentation shall ensure a system can be validated. The procedures followed and documents generated by Absolute Control are GAMP5 compliant and open to inspection and audit.

Please contact us for further information or e-mail info@absolutecontrol.ie