Supplier of wireless searchlight controls suitable for most brands and types

System description

General system features

433MHz ISM band operation Range of minimum 400m line of sight
Two standard operator panel versions Encryption and frequency hopping
Custom layout an design on request All electronics has -40°C to +85°C range
Digital and analog I/O Ethernet and serial bus (RS422/485)
Multi receiver time-slot communication Multi-antenna redundancy over Ethernet

System structure

The remote control system is a highly flexible structure that can be tailored to a variety of different configurations depending on user demands. The drawing show a typical full scale configuration which may control a group of different searchlights, from ethernet connected searchlights like Norselight R50 and R60 or serial bus connected searchlights like Francis FBUS to simpler searchlights with direct motor control. Our different adapters allow full control of all types from the same remote control panel regardless of the differences. An operator may then control up to 6 different types of searchlight and searchlight brands from one standard remote control panel.

The image show an example of a searchligt configuration as described in the text. Klick on the image to get a bigger diagram.

The main parts of the system is the remote control panels (SWOP) and the receiver modules. The receiver modules may be fitted with different adapters depending on the target searchlight. The receiver and suitable adapters may also be delivered as one enclosed unit for outdoor mounting, indicated by the receiver (blue) and adapter enclosed by a black line.

Basically, a remote panel may connect to 1 of 6 different searchlights by selecting the appropriate searchligh number on the panel. The selected searchlight will now be indicated on the LED-bar.

After switching, the new searchlight will be under operator control within a few seconds provided the searchlight is free for control. As a system may have up to 50 attached panels, only one panel can however have control of a specific searchlight at a given time. A panel gaining control of a searchlight will keep the control for 10 seconds after the last operation. After 10 seconds, any panel may take over the control. Whether you are in control or not is shown on the SYS indicator on the panel.

A receiver may control only one searchlight or all searchlights, depending on the type and number of attached adapters and how they are configured. With ethernet or serial adapter, one receiver may control up to 6 ethernet or FBUS connected searchlights, while using simpler MINI- or MAXI-adapters, up to 3 searchlights may be connected to a single receiver.

The system uses time-multiplexed communication, and to avoid collision on the air, one receiver will act as master and synchronize the others. This job is automatically done by the receiver controlling searchlight no.1. As a consequence, searchlight 1 must always exist on a multi receiver system, even though it may be configured as a dummy searchlight and made unavailable from the panel. In single receiver systems, no synchronization is needed and in this case, it doesn't matter if you have a searchlight no.1 in the system or not.

Mutlti antenna configuration

Sometimes, it is necessary to extend the coverage of the remote system, either due to long physical distances or due to shielding between parts of the system, for example if the system is to be operated on different decks of a ship where the metal structure of the ship will make direct communication to a single antenna impossible. To solve this problem, the system offers a multi-antenna option.

As shown on the drawing, one receiver is set to be the multi-antenna master by setting a strap on the ethernet-adapter. The other receivers in this group are set to be multi-antenna slaves by setting an other strap. In such a setup, the whole master-slave group can be seen as a single receiver to the operator, as indicated by the dotted gray line. It is also seen as a single receiver by the other free standing receivers. Whether the multi antenna master is controlling searchlight no. 1 and thereby automatically acts as master for the other free standing receivers, or if one of the other receivers act as master, is not relevant. Theoretically, one might have up to 6 free standing receivers, each with up to 6 attached slave antennas. But they still only act as 6 searchlights to the user.

With the multi-antenna configuration, the signal from the control panel will be received by all slave-receivers within range and passed on to the master receiver, thus giving redundant recepetion in addition to larger coverage. In addition to giving a better coverage, one will also experience a more stable reception as local noise or fading will have less impact on the operation. If one receiver looses a message from the remote panel due to noise or fading, there is big chance that this message is received by any of the slaves and passed on to the master. Retur messages to the remote panel can only be sent by one transmitter to avoid interference and the return transmitter is selected automatically by the master based on which receiver that had the strongest and best signal.

The routing of incoming and outgoing signals in a multi antenna receiver configuation is done automatically 5 times a second and gives a seemless transfer between antennas, much like roaming in a modern mobile systems.

It is however important to remember that all the free standing receivers can be regarded as the top level in this hierarcial structure and that a multi antenna receiver group has the same priority and functionality as any other single free standing receiver. In fact, it is only multi-antenna masters that act as a receivers to the system and it is the setup of the multi antenna master receivers and their attached adapter cards that define the function of the receivers and which searchlights that they control. The slaves are as the name implies, only slaves, relaying communication between the multi-antenna master and the operator panels. Multi-antenna slaves usese ethernet-adapters, but only for communicating with their multi-antenna masters. Slaves can never control a searchlight, this can only be done by a multi-antenna master.

Safety features

As a safety feature, all remoter control panels that is to be used with the system, has to be "paired" with each receiver that it will need to communicate with. For the multi-antenna setup, only the master receiver has to to be paired with the control panel. Only control panels paired with a receiver can control searchlights attached to that receiver. When paired with a receiver (or a multi antenna group), it has access to all searchlights connected to that receiver. The pairing is linked to the receiver and not to the individual searchlights.

All communication is also encrypted and useses checksums to discard any damaged or illegal messages, in addition to discarding control panels not previously "paired". This prevents any searchlights to be controlled by any external, non authorized control panel, regardless of wether it is an accidental interference or targeted attempt.

Also the system uses frequency hopping to avoid beeing blocked by any single channel jamming. Frequency hopping also help to minimize problems with signal fading as the results from fading act differently on different frequencies. The chance of having worst case conditions an all hopper-frequencies at the same time is minimal, thus giving av more stable communication.

The system can operate in any of 6 different channel groups and it is recommended that systems which should operate near each other, but not share panels or searchlights, should use separate channel groups to avoid any interference between the systems, interference that may otherwice jam the system.

Example setup

Please click HERE for a description of the example setup.