Light curtain saves time and safeguards worker wellbeing

Light curtains can be the last line of defence in a food and beverage manufacturing plant, especially in operations that require cutting, chopping and packaging of produce.

Jack Wheatley is the product manager for safety, sensing and signalling for NHP, an electrical engineering company that specialise in electrical and automation products, system and solutions. NHP offer unique products such as Allen Bradley GuardShield light curtains that help to improve the safety in food and beverage manufacturing plants. He knows how they can be used best within factories that produce food and beverages.

The Allen Bradley GuardShield range of light curtains has a few special features that are designed to make them not only cost-effective, but also reduce the investment required in maintaining spare parts.

Typically, a light curtain is used on machinery or production lines where regular access is required. Operators don’t want to be restricted by having to constantly open and close guards. They want to have access to the area, whether it is during production or during a downtime.

Being a transceiver and receiver, many light curtain installations require two separate light curtain sticks. The Allen Bradley GuardShield curtain leverages patented plug in transceiver technology where each stick can be used as a transmitter or receiver via the innovative plug-in modules.

“The concept of this design is to minimise on parts required,” said Wheatley.

“This new design reduces the number of parts required and will allow customers to better maintain production facilities with fewer spare parts. Additionally, for a supplier to keep stock, it’s about having the ability to hold a single length curtain, plug in module, and better service the market.

“Additionally, the patented plug design has embedded functions which are configured quickly and easily via DIP switches or software, significantly reducing engineering effort. These include: muting, blanking, start mode, external device monitoring (EDM) and scanning ranges” said Wheatley.

Another feature that Wheatley has highlighted is the laser alignment capabilities, which give the user an enhanced Integrated Laser Alignment System (ILAS) for quick installation and reliable operation.

“This cuts installation alignment labour time significantly, which is a significant benefit across multiple installs,” said Wheatley. “Prior to having this embedded technology, it was a tedious task for customers”.

Wheatley said that the most exciting feature is the Allen Bradley GuardShield being the first safety light curtains on the market to be Ethernet-enabled.

“With the release of the 450L-ENETR Ethernet adapter, detailed diagnostics and status information will be conveniently available to customers when integrating into a networked PLC system,” said Wheatley.

“At NHP, we understand that all equipment as part of a food or beverages manufacturing process is critical to its operation and maintenance crews require reliable components along with product support. This is one of NHP’s key values when going to market,” said Wheatley.

“NHP has a product technical phone service that all customers can access for engineering support,” he said. Further to that, Rockwell Automation, who manufacture the product, also have a paid service technical support hotline.

The units come in different lengths ranging from 150mm up to 1950mm – in multiples of 150mm in both 30mm and 14mm resolutions. There are no dead spots (passive zones) at the top or bottom of the stick, which means they can be installed inside a machine frame and do not have be mounted outside/on the machine like a traditional light curtain system.