Datalogic Scanning STARGATE - Manual (Page 10)

STAR H GATE™
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Features Benefits
•
Seamless Active Roaming • Wide area coverage
• Up to 2.000 RF devices supported
Gryphon™ Mobile series
Dragon™ Mobile series
Formula 734 RF Pocket Terminals ( * )
Formula 725 RF Hand-Held Terminals ( * )
Formula 660 RF Pen Terminals ( * )
• Up to 16 STARGATE™ RF base station
network
• STAR-Link™ software for Windows
• Real time connection with your
application
• Wide range of different
devices able to solve different
applications in different
markets
• Reliable, Fast & Cost-Effective
system
• Full & Easy Windows based
application integration
( * ) not compatible with STARGATE™ USA model
STARGATE™ does not carry out continuous polling, but it is enabled each time an
RF device sends it a sequence of data. This means the radio channel is always free
when RF devices are not transmitting.
The media access protocol used to manage the shared RF channel is called Carrier
Sense Multiple Access Collision Avoidance (CSMA/CA). Once the RF devices have
tried to send data to STARGATE™ simultaneously, the system enables a
transmission delay allowing both of them to communicate with the base station.
The Datalogic CSMA/CA protocol manages the data transmission between
STARGATE™ and the radio device using a 16-bit CRC checksum. Once the
sequences are received by STARGATE™, the base station stores them in its internal
memory until they are requested by the PC.
The communication between STARGATE™ and the PC takes place through a
proprietary binary protocol avoiding collisions on an RS485 line and providing a
16-bit CRC checksum to guarantee information integrity.
The application program running on each RF device must implement the CSMA/CA
protocol, while the PC must run a Data collection software program based on the
STAR-Link™ software tool.
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