The SMG (Slotted Microwave Guide) data transmission system is suitable in automation technology for contactless and interference-free transmission at high data rates up to 10 Mbit/s for all track-guided vehicles and opens up a wide range of applications through its variable design.
SMG was originally developed by MBB (Messerschmitt-Boelkow-Blohm), now DASA (Deutsche Aerospace), to transmit data to the magnetic levitation train (»Transrapid«) travelling at speeds of up to 250 mph. VAHLE acquired this product by the end of 1994 and now has over 1000 installations successfully in operation worldwide.
VAHLE has embarked on an extensive development programme to increase the SMG application range. Presently there are already data interfaces available for the most commonly used bus systems. Heavy-duty construction makes it possible to install SMG in arduous and environmentally difficult locations; for instance, a great number of SMG waveguide systems are function reliably in steel mills, foundries and harbours.
The SMG data transmission system operates economically with single channel transmission and low data rates. Modular design easily expands the system to handle at relatively low cost medium and high data rates as well as multi-channel configurations. When combined with VAHLE conductor systems for the current supply, SMG data transmission systems become a reliable high-performance component package capable of handling a wide variety of applications as demanded by current and future automation technology.
The SMG system is designed for the transmission of digital, serial data, as is generally typical in data communications networks, as well as for the transmission of video signals. Special transceivers (transmit/receive devices) with interface modules for all common bus systems prepare the digital serial signals for transmission by means of frequency modulation.
For full-duplex transmission of the usable signals, two carrier frequencies in a range of around 2.4 GHz are available. A specially shaped aluminium extruded profile (slotted hollow conductor) between the transceivers is used as the transmission medium.
Through the transparent layout, as well as the support of numerous data protocols, the SMG system can be integrated into existing bus systems without a problem. If needed, VAHLE also provides suitable engineering services for this purpose.
SMG Special Features
- Immunity to interference due to isolation of the SMG profile from the surroundings
- Maintenance-free due to contactless transmission technology
- Common assembly of the SMG profile with all VAHLE current conductors, Powerail conductors and the CPS system
- Error-free transmission of high data rates up to 10 Mbit/s
- Simultaneous transmission of up to six data channels full-duplex
- Transmission paths of up to 1000 m without intermediate amplification due to highly dynamic transceiver response
- Simple adaptation to the customer's computer peripherals, as well as good expansion possibilities due to modular device construction
- EMERGENCY-OFF transmission according to stop category 1, safety level 3
- Coupling of several mobile subscribers to one SMG profile
- Transmission that is independent of mobile subscriber's travelling speed
- No negative effects on transmission quality due to environmental influences, e.g. temperature, humidity, clouds, dust etc.
- Also suitable for tracks with curves, breaks and switch points
The SMG data transmission system provides many interfaces for the most common bus systems (RS 232 C, RS 422/485, Ethernet, Allen-Bradley Data Highway Plus, Allen-Bradley remote I/O, GE Genius and many more), as well as special interfaces for video, audio, control signal and emergency shutdown transmission. All interfaces are formed as plug-in modules and thus can be easily adapted to the existing communications structure.
The SMG-SES/SEM transceiver unit is equipped with an RF module and an 24 VAC/DC power supply module. It is designed to accept the SMG-DM data module.
Data module SMG-DM:
The SMG-DM data module is prepared to accept the SMG-DM interface module and is equipped with a connector for the customer's existing communication systems.
Interface module SMG-SM:
The SMG-SM interface module is used to adapt to the serial data signals of the customer's existing communication system.