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ServoWire
is easy to install ...
Thin serial cable
technology included in IEEE-1394 open standard slashes
interface costs.
ServoWire dramatically reduces the
installed cost and hassles of system wiring. A traditional servo
system has 20-25 connections per servo axis, all of which are
necessary for proper system operation. ServoWire eliminates
hundreds of electrical signal terminations with simple,
plug-together cables.
The cable
and connector design are also part of the IEEE-1394 open standard
and are essential technology to delivering the high-speed
serial bus communications. Highly engineered and reliable, the
cables and connectors are patterned after those made by Nintendo
for their Gameboy units.
Standard 1394 cables contain two power conductors, and two
twisted pairs (TPA and TPB) for data signaling. Each signal pair
is shielded and the entire cable is shielded. Cable power is
specified to be from 8 to 40 VDC at up to 1.5 amps and is used to
provide interface power for drives connected to the bus.
Molex shipped the first 1394 cables, connectors and headers
for use in products, and also played a key role to insure that
the entire mechanical and electrical designs would be included in
the IEEE-1394 standard to guarantee compliant second-source
cables would be available.
ServoWire® utilizes plug-n-play technology to bring ease of use to
a new level.
IEEE-1394 implements a "tree" topology, with repeater hardware in each
interface rather than a ring (so there is no need for terminators or a hub). The tree
structure, and the fact that 1394 uses automatic ID assignment, eliminates the need to set
physical addresses before attaching a new servodrive to the network.
ServoWire® uses "plug-n-play" technology provided by IEEE-1394 to expedite
setup and commissioning of devices on the ServoWire® network. With a ServoWire®
system, the
ORION controller searches for servodrives on the network at power-up. Servodrive IDs are
displayed on the drives seven-segment LED, and incorrect or unassigned IDs flash
until resolved by pressing a button on the drive to select the correct ID. Drive
parameters are then downloaded as defined by the software, and can match a single
servodrive to a wide variety of motors.
This approach simplifies replacement of servodrives in the field. New drives are
installed "as received" since off-line, computer-based setup is not required to
properly configure the new unit. The installer simply selects the appropriate ID, and the
servodrive "self-configures" --- reducing spare parts and setup complexity.
The fact that 1394 cables provide power for the ServoWire®
interface in the drives
allows the network to operate, even without power to some of the drives in the network.
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