Safety transceiver uses only three beams to cut manufacturing costs

05 January 2010

Two ranges of multiple light beam devices (MLD) from Leuze electronic have been designed with a three-beam transceiver which replaces more traditional 4 beam devices and cuts manufacturing costs.

Leuze MLD

At launch there are two ranges in the MLD family. The MLD300 provides a Type 2, SIL 2 product while the MLD 500 is a Type 4, SIL3 device. Within both ranges, there are three different levels of functionality, much like the different trim levels offered for a particular model of car. Continuing the theme of a car range, the most basic MLD 310 or MLD 510 models offer functions like automatic reset and LED display which previously have only been available on more expensive units. The MLD 320 and MLD 520 models offer start/restart interlock, contactor monitoring and configurable operating modes, with the range topping MLD 330 and MLD 530 the most ‘feature rich’ offering integrated control of parallel or sequential muting for example. All of the features are selected according to the units wiring connection so there is no need to configure the devices using a PC.

Extras such as integrated laser alignment at the top and bottom of the columns, or an integrated muting lamp can be added to numerous models. MLDs are widely used in a variety of applications ranging from simple access guarding, to safeguarding combined with muting for example at points where pallets leave guarded areas, and wide-area perimeter guarding.

The MLD family includes transceiver models which are ideally suited to access guarding and safeguarding with Muting. A transceiver is a combined transmitter and receiver in one unit, with the other column being a passive reflector which does not require an electrical connection. Transceivers are popular because they offer cost savings at installation needing only a wired connection on one side, namely at the transceiver.

Traditionally transceivers have been two- or four-beam units because the reflecting column works like a periscope with a mirror reflecting the incoming signal down the inside of the column on then back out to the receiver from a mirror at the bottom. A four-beam system is therefore a two-beam system in the top half of the column and another two-beam system at the bottom.

In many applications a two-beam system does not provide adequate protection of the machinery and the next step up is a 4 beam system in order to get a middle beam.

Leuze electronic’s innovative three-beam MLD transceivers use technology from its multi-beam light curtains to precisely switch the two transmission beams so that they can be detected and identified by a single receiver unit. This innovation reduces manufacturing costs, which combined with other design features such as optics within the end-caps, enables the MLD family of Multiple Light beam safety Devices to offer more features for less money than the units they replace.

The two- and three-beam transceivers have a range of 8m, but the both MLD 300 and MLD 500 series include two-, three- and four-beam transmitter and receiver systems, which offer a range of 70m.

Installation is made easier and hence quicker by a new patented mounting system which provides full flexibility in the choice of mounting height within the matching device columns rather than being constrained by the position of pre-drilled mounting holes. The MLD units can also easily be aligned using the new bayonet style of swivel mount which enables swift alignment and provides reliable mounting – examples of Leuze electronic ‘the sensor people’ providing industrial solutions that reduce costs.