Group controller



The GST-XT group circuit board is a traffic control computer for FST controllers manufactured by NEW LIFT. It enables the interconnection of individual FST-Controllers into a group. The GST-XT group circuit board is suitable for the use of controller models FST(-1), FST-2, FST-2XT and FST-2s. When converting older group controllers of the FST product family, the current software of the FST-Controllers is mandatory. The GST-XT group circuit board is located in a separate housing in one of the control cabinets of the group members. Installation takes place on a TS35 rail. A separate 24 V DC voltage supply (switching power supply) supplies the GST-XT independent of the FST group members and is, thus, separate from their voltage supply. For processing the group control algorithms, the GST-XT has a 32-bit processor and a Neuron processor, which is responsible for the LON activities. The GST-XT is equipped with a serial interface that offers all lifts of the group a central modem or fax connection possibility. The RS232 serial interface of the GST-XT enables the connection of a PC to the lift group for monitoring and remote control by means of the ELEVISION lift monitoring software as well as the connection of a fax modem or a protocol adapter module (PAM) for evacuation controllers. Depending on the number of BUS members of the shaft bus, it may be necessary to use a power repeater. This galvanically isolates the BUS modules from the GST-XT or FST and amplifies the supply voltage as well as the data signals. The integrated SD card interface enables recordings, which are useful for traffic analysis. Should it be necessary to update the GST-XT software, a USB connection is available for convenient updates by means of a USB stick (optional).

LON technology

All electronic assemblies of the FST are based on local operating network technology, abbreviated LON technology. This open network technology is used, in particular, in building automation. Communication is via a serial bus, the so-called LON bus. The processor assembly of the FST main circuit board coordinates all data traffic of the lift system from the control cabinet. The LON bus is looped through from electronic assembly to electronic assembly with pre-assembled, four-core cables. External data exchange is subject to the standardised protocols of the LonMark standard.


The GST-XT group circuit board likewise makes optimised use of LON technology, which is implemented in the FST controllers. By means of this technology, the GST-XT becomes aware of all activities on the LON bus and, thus, of all measured and actual characteristics of all lift systems participating in group mode. Thanks to its 32-bit computing power, the GST-XT can intelligently process this information and thereby ensure efficient traffic management of all group members.

A mixture of automatic and configurable functions lends the GST-XT a unique level of flexibility, even for the most demanding installations.

The incoming calls for the shaft bus are processed further by the GST-XT and calculated taking into account a number of criteria of the group algorithm. Based on this group algorithm, the GST-XT then distributes the calls to the individual FST-Controllers within the group.

In the unlikely event of a GST-XT failure, an emergency program within each FST controller takes over the drive commands. For installations that require a high level of readiness, a multiple-redundant group controller option can be integrated by mounting at least two GST-XT group circuit boards within the group. In the event of a system failure of the primary GST-XT, one of the secondary GST-XT takes over the group controller function.

Stored in the GST-XT memory are copies of the parameter sets of all connected FST-Controllers. In this way, the GST-XT can include information about door times, drive curves, drive calibration data and shaft dimensions of the individual controllers in the group algorithm.

If control parameters are changed in one of the FST menus, this is automatically detected by the GST-XT and a copy of the changed parameter set stored in memory.

Should it be necessary to change date and time settings on a controller, all controllers of the group accept the new time settings in synch.

Technical data

The GST-XT consists of an FST and the GST-XT group circuit board, which is installed in a separate housing. Power for the GST-XT, as well as the shaft bus and its members, is supplied by means of an external 24 V DC mains device. As a result, the GST-XT remains switched on even after the FST is switched off. Not until the shaft bus input (F6) is switched off is the GST-XT de-energised.

Supply voltage 24 V DC ±10%
Typical power consumption 300 mA
Outputs Short circuit-proof
Length x height x depth 126 x 118 x 45 mm
Temperature range: Storage & transport / operation -20 – +70 °C / ±0 – +60 °C
Relative humidity: Storage & transport / operation
+5 – +95 % / +15 – +85 %
Protection type IP20

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