Yaskawa SmartTrac PCIM Card - Manual (Page 10)

SMART TRAC Genius PCIM Card
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Genius Basics Technical Manual 3554-0080
Genius Network Topology
Configured in a bus topology, Genius networks require no special equipment to
amplify or regenerate the signal. Transfer of information occurs across cables
via RS-485 serial modems. You must terminate each end of the bus. A Genius
network will support up to 32 devices at 153.6 Kbaud standard, 153.6 Kbaud
extended, or 76.8 Kbaud and up to 16 devices at 38.4 Kbaud.
You may arrange devices on a Genius network in any physical sequence on the
bus. For efficient communications, however, arrange devices in the same
sequence as their Node (Block) Numbers.
Cabling
Cabling a Genius network consists of single twisted pair shielded cable, daisy-
chained bus cable or fiber optic cable. RS-485 serial modems transmit and
receive data node to node. With simple field wiring to and from a Terminal
Assembly, the cost of wiring and cabling a Genius network is relatively low.
Network Length and Cabling
The maximum bus length depends, in part, on baud rate. The maximums are:
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7500 feet at 38.4 Kbaud.
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4500 feet at 76.8 Kbaud.
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3500 feet at 153.6 Kbaud extended.
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2000 feet at 153.6 Kbaud, standard.
The maximum length at each baud rate also depends on cable type. See
references in the Appendices for a complete list of cable types, showing
corresponding bus lengths and baud rates.
Greater bus lengths are possible using sections of fiber optics cable with mo-
dems.
Terminating Resistor Specifications
You must install 75, 100, 120, or 150 ohm, 1/4 watt resistors at both ends of the
electrical bus cable. Resistors must have a tolerance of -10% to +20%