Wire, it would appear, is on its way out, at least judging from two new LMI products from third parties. New products are doing away with the need to wire up every sensor direct to the LMI. With that comes greater freedom to build cranes and other machines.
LSI’s new wireless crane sensor range
Load Systems’ GS550 communicates with its sensors without wires. Antennae a couple of inches high (20mm) transmit data up to 3,200 ft (1,000m) from a load pin or boom angle sensor back to the central unit. Individual sensors only transmit by line of sight. But each sensor unit can also work as a repeater, passing on any line-of-sight transmissions to another unit, and so on. Standard sensors include load pins, line riders, load cells, angle sensors, wind speed indicators, anti-two block indicators and boom extension cable reel. A slewing sensor is not currently available.
The GS550 system is factory-installed on Link-Belt’s TCC 450 tele-crawler, launched last year, and other customers include Manitowoc Crane Care and Barnhart Crane and Rigging, which fitted one on a Demag CC1200 crawler crane.
Hirschmann’s Mentor system works off a CAN-Bus network, which operates like a computer network in an office. This reduces, but does not eliminate, the wires – a twisted pair of wires connect individual sensors to a single network cable, which carries all of the data to and from the computer. But its great advantage is that the way they communicate is standardised using the CAN-Open protocol. So users could potentially run a load pin, anti-two block, boom extension and angle sensor from different manufacturers, provided all have a CAN-Open interface. This flexibility makes ordering spares and replacements easy, and simplifies set-up. CAN-Open sensors available from Hirschmann include pressure transducers for hydraulics and angle sensors.
Load Systems claims that its battery-powered sensors have at least two years of battery life with the shipped lithium D battery. Users can get up to a year of life with regular alkaline D batteries. The system monitors up to 32 sensors with programmable limits. The sensors transmit over a spread spectrum in the 905-930MHz band in the USA, and the 800MHz band in Europe.
Both systems come with either a numerical display, or a graphical display. The Hirschmann Mentor QVGA comes with a 320 x 240 pixel display whose contrast automatically adjusts depending on temperature and brightness. It has four digital inputs, four digital outputs, and four other slots for inputs or outputs. LSI’s new graphical display is expected to launch in May or June. Unlike previous versions, it will not have a touch-sensitive screen but will have keypad buttons beneath the display.
LSI’s new wireless crane sensor range LSI’s new wireless crane sensor range
