Electricity + Control February 2016

CONTROL SYSTEMS + AUTOMATION

Safe software reporting Most safe software platforms provide a Cyclic Redundancy Check (CRC). This is shown as hexadecimal number. Once the final software configuration is complete and compiled it will generate this CRC number. This number is unique to the configuration at that time, any further changes will generate a different CRC number Therefore the recording of the validation test must include the CRC number.

Figure 7: Example Rockwell GuardLogix.CRC (Rockwell calls the CRC ‘Safety Signature’).

Ian Hetherington is a certified machine safety engineer. He provides design, specification and CE certification of safety systems. Also independent analysis and validation of safety systems. Technical files are auditable and verifiable to ISO/ IEC and SANS standards. Projects are undertaken in South Africa, Europe and United States.

Enquiries: Email ian@vantage-control.com

Figure 6: Example Siemens Step7-F. CRC (Siemens calls the CRC ‘Collective Signature’).

CONTROL SYSTEMS + AUTOMATION

ROUND UP

Using wireless products in hazardous areas

SolexyWireless from RETAutomation Controls has released the new RX series antenna coupler, making it easier to use wireless products in hazardous areas. This unique design is the only barrier design that is Explosion Proof with an internal Intrinsically Safe Barrier, and allows you to use a standard passive antenna or a cable run to a remote antenna. No glands and no space inside the housing are required.This bar- rier is mounted into the enclosure wall, providing the flame proof protection. In one product: • Explosion proof sealed fitting • Intrinsically safe barrier • RF pass through The Solexy RX series explosion proof and intrinsically safe RF Barriers are an integrated protection device that facilitates passive antenna installation in hazardous areas making the signal intrinsically safe. The patented RX series barrier features a barrier circuit which pro- tects the antenna connection and field cabling from faults or voltage and current high enough to cause a spark ignition. The RX circuit is encapsulated and housed in an explosion-proof stainless steel body

and is designed to be used with a listed enclosure for hazardous areas. The RX offers new advantages over the legacy AX series. An engineered co-planar circuit design, and tuned to tighter frequency ranges reduces in insertion loss as much as 50% or more. The longer housing keeps the antenna radiation pattern away from the housing to allow for a more dependable signal. The RX series also has new ratings for IECEx and ATEX. It is now approved as an Apparatus. This will cut down on costly Notified Body evaluations. The new RX series has a list of installation parameters and when followed you can use this without requiring additional evaluations. Enquiries: BrandonTopham. Email brandon.topham@retautomation.com

Electricity+Control February ‘16

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