Electrified Monorail and Floor Conveyor Controller

LJU's main business since 1986 has been Electrified Monorail Controllers. Co-operation from the outset with end users, significantly in automotive manufacturing, enabled the first generation of LJU controllers to have combined features, which were innovative and detailed within the systems supplied, specifically for the mobile drive technology being utilised or planned for production operations.

LJU's concept is based on the synergies of the following:
  • Long term experience - 30 years of design and manufacturing
  • Dedicated hardware architecture - developed fit for purpose
  • Specialized firmware - developed fit for customer requirement or Soft-PLC (in Series 8)
  • Migration projects by Technology Partnership with Rockwell Automation (see below Open Hardware Program)
Readily applied and configured the subsequent operation of an Electrified Monorail System (EMS), implemented by many global end users, is not as easy as it appears at first sight. However, LJU technology enables superior efficient operation and clarity of function.
Compact Controls Series ST-870

The compact multi-functional controller ST-870 successfully combines complex technical features and a modern functional design at the lowest possible price.

The controller internal software stores several typical EMS processes that are easily parameterizable and whose functionality has been tested in more than 1500 EMS systems worldwide. These EMS processes therefore do not need to be reprogrammed or reverified. There are various alternatives for parameterization and programming: via infrared, via Bluetooth or over the rail bus/inductive bus, compatible with older systems as well.

In the enhanced model ST-89x, devices can be fully oriented to end customer specifications or adapted to meet the specific requirements of equipment manufacturers. This extends to the design and construction of low-temperature devices which can be used in cold stores. A modular safety architecture permits solutions at SiL 3 and Performance Level D, as also at Performance Level E if peripherals are appropriately designed.

The number of inputs/outputs is fixed for controllers of the ST-870 series and suffices for all standard applications as well as many special applications, even with sensors such as position measuring systems or distance sensors connected via an RS-485 interface.

▶ 8 digital inputs (multi-configuration)
▶ 2 digital outputs
▶ RS-485 for external devices
▶ USB for data-com stick
▶ Infrared

Controllers of device class ST-89x use an open programming environment, enabling the end user to implement its own concepts or expand and modify existing programs. The implementation of real-time operational data logging and configurable data logging considerably expands and facilitates auxiliary processes such as preventive maintenance and remote service. Controllers are equipped with a plain-text display which reports status messages and error conditions in the language of the user.

Commands are sent over a full-wave/half-wave/PCM/rail-bus controller, and this is therefore fully compatible with earlier LJU systems as also with a large number of devices from other manufacturers.

The motor control drives both control procedures for classical 3-phase asynchronous machines in all commonly used voltage variants as well as permanent magnet synchronous motors (PMSM) and brush-less DC motors. Jolt-free acceleration curves and a variety of positioning routines round off the concept in detail.

For further information please refer to our download area.

Inverter Controls Series ST-8xx        New Design - New Technology - New Features

Though basic features of an Electrified Monorail and similar transport installations in industry and logistics do not change significantly over years there are a couple of modifying requirements as time goes by. This pertains dynamical operation demands, more comprehensive diagnostic capabilities, additional energy saving options as well as raised safety characteristics and last but not least also standards of design for devices. By realizing Series 8 of LJU controls these devices shall be fit for the future and should again be trend-setting in this special market segment.

Click the graphics to enlarge!

For further information please refer to our download area.

Open Hardware Program / Rockwell Automation partnership

Simplify. Collaborate. Innovate. That is a key roadmap of one of the largest Global Players in automation.

In a Technological Partnership with Rockwell Automation LJU provides skillet or monorail controller designed to serve special markets and projects. Using top rated technology components of RA (as industrial electric motor drive, relay, safety relay, motor protector, power supply, switches and other key components) melds LJU's long term and worldwide special application experience with RA's outstanding general capabilities of a global automation player .

The design includes compatibility with stationary LJU control components in existing installations for retrofits or tailored future new projects. State-of-art safety features as STO (safe torque off) and other functions are integrated.

For further information please get in contact with our sales or service representatives!

Inverter Controls Series ST-7xx     More efficient and self protecting power circuits

Controllers of the series ST-79x are programmable trolley controllers with integrated frequency inverters for Electrical Monorail Systems (EMS). These controllers are used for controlling drive, hoist and/or conveyance motors. Individual controller functions are standardized into function modules and are compatible with various systems; when used individually or in combinations. The drive motors can be operated asynchronously (e.g. for general transportation tasks) or synchronously (e.g. driving in assembly lines). The controllers could have multiple inverters that could drive sequentially or in parallel depending on the requirement of the application and the model of the controller. The communication or transfer of commands to and from the system controller takes place over

  • Rail bus (RB),
  • Inductive data bus (iDB),
  • PCM or
  • Half-waves

Application software and the operating parameters can be transmitted to the controller via infrared using the handheld programming device MU 705. This allows quick and customized solutions for different system concepts and application scenarios. For functions like manual movement of the trolley, the controller can be remotely operated using the infrared remote control. Important trolley characteristics required for reliable operation are continuously monitored by the controller. In the case of a fault, the trolley is put into a safe operating mode (disabling all movements). Moreover, different messages are displayed on the trolley controller display and sent to the system controller.

Inverter Controls Series ST-6xx     Multiprocessor devices with enhanced diagnostics and communication

Controller of Series ST-6xx follows basically the concept of the successful Series 5. On the face of it both series do not look very different, the internal configuration, however, has been revised significantly. Contrary to the single processor concept of Series 5 the Series 6 has been designed as a multiprocessor architecture, i.e. all internal components like inverter board, sensor board, relay boards and CPU boards are communication via internal LJU bus. This is based on a simple RS-485 and also local external communication partners like rope encoders or position readers can be linked very cost effective to the controller CPU. There are a lot of 3rd party devices available on the market with standard available RS-486 with LJU bus protocol.

Inverter-Controller of Series 6 (ST 69x) are on market since mid nineties and may still be available in single spare part figures, as key parts are obsolete on the regular market. On request there are "form-fit-function" compatible devices available or can be projected and manufactured as required.

Triac EMS Controller of Series 6 (ST680/646) can still be provided.

Inverter Controls Series ST-5xx     The trailblazers of monorail inverter controllers

By delivery of controllers Series ST59x in 1990 started an era of new compact inverter controllers for Electrified Monorails. Built as easy single processor solution it was first time presented instead of triac and relais controllers an integrated 400V inverter board. By means of that it was possible to realize new functionality like synchronous drive in assembly lines without synchronizing chain or operating with more than only two speeds. With the left pictured controller of the company FATA in Torino/Italy this functionality was first realized in industrial environment. This controller was one of several brand labels of an LJU box, as also done with some other companies as e.g. Digitron Switzerland at this early time of LJU history.

Devices of Series 5 have been delivered to the market until mid nineties into new projects. They can be repaired today on a case-by-case-basis, but cannot any longer be produced due to many obsolete parts. On request LJU will offer design and delivery of functionally compatible devices.

Triac-Controller ST680, ST646    The simple technology - Switch on/off/over by Triacs

The control system ST-646 and ST-680 is a microprocessor-controlled freely programmable vehicle-control system for pole-changing asynchronous motors - 2 speeds - in electrical overhead conveyor systems with 6 (8) rails. With it, two asynchronous forward speeds and the operating state "Open brake" can be realized - pre-specified by means of a PCM drive command. The separate motor coils and brake coil are controlled via triacs. By varying the operating parameters, vehicle acceleration and braking operations are possible almost completely without jolting. With the aid of infra-red data transmission by means of the hand held programmer (MU-505), the software and hence the control system can be optimally adapted by the operator in a simple way to very many system concepts / application cases. The control system monitors fundamental sources of error in the vehicle and, if an error occurs, it outputs an unambiguous message via the 7-segment display as well as a composite error message via the signal rail to the controlling PLC. The individual functions are standardized in hardware and software and designed in a system-independent way.

Track Switch and Lift Controller
The WST is a decentralized unit for actuation of a (track switch) motor with analysis of the two end position initiators "track switch straight"/"track switch curved". Depending on the particular end position and configuration, up to 4 safety locks are activated. The exchange of commands and status information can, depending on the model of the controller, take place via the LJU-LM bus (LJU-power module bus) or via an external field bus. Important track switch components components, which are necessary for defect-free operation, are constantly monitored by the controller. In case of a defect, the trolley is put into safe operating mode (disabling all movements). The error status of the track switch is displayed by a signal lamp on the WST and on the PLC. If the track switch receives the command to move (depending on the system, by the LJU bus master or field bus), the track switch moves to the required position. When the track switch is moving, all safety locks of the track switch are cut off from the power, until the track switch reaches the intended end position (detection by the particular limit switch). When the track switch reaches their position, the power is switched on and the corresponding track is reconnected.
Retrofits or Substitutes for all old installations and controllers
There is barely another company more constantly, more intensely and most innovatively engaged in this market of Control technology for industrial conveyors like LJU since the late 80's. Many companies wich were active in this field as time went by went out of market or turned over to other business fields. For many operators of monorail systems this is a problem as they are facing a lack of service for their installed base. LJU therefore has been contacted many times to provide compatible replacements and can do in most cases. If you are facing this kind of problem - don't hesitate to contact us for replacement solutions!

LJU has 30 years of experience as a reliable supplier for automation integrators, relative to the tailored control and communication solutions on mobile transport carriers in Electrified Monorails or Electrified Floor Conveyors.  The range of products are researched, designed and manufactured using proven range of components configured according to the demands of the end user company or organisation. 

LJU are your reliable partner for standard and special solutions now and in the future!