Sun Microsystems Enterprise Tape Library 7/3500, Field Service Manual

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12 Sun Enterprise Tape Library 7/3500 Field Service Manual • July 1997
Gripper Interconnect PWA
The gripper interconnect PWA acts as a distribution/interconnection point for
signals from the gripper motor, CIG transmitter PWA, CIG receiver PWA, and bar
code scanner PWA to the gripper umbilical. The gripper open and closed sensors are
mounted to the Gripper interconnect PWA and also are routed to the gripper
umbilical. The gripper umbilical plugs into the extension carriage interconnect PWA,
which buffers the low-level signals and routes all signals down the Y-umbilical.
Gripper Motor
The gripper motor raises and lowers the upper gripper jaw. The gripper motor is a
2-phase stepper motor with 1.8 degrees (0.005 inches) per step resolution.
Cartridge-In-Gripper Receiver PWA
The cartridge-in-gripper (CIG) receiver PWA contains two synchronous photo-
detectors located at the front and back of the lower jaw. The CIG receivers are
positioned to enable the robotics controller PWA to determine if a tape cartridge is
fully gripped. If the front CIG receiver only is occluded, the cartridge is partially
gripped. If the front and rear CIG receivers are occluded, the cartridge is fully
gripped.
The outputs of each of the CIG receivers are ORed together to drive a red LED
transmitter as part of synchronous break-beam detection system. The pulsed light
from the CIG transmitter shines across both CIG receiver sensors on the lower
gripper jaw.
Cartridge-In-Gripper Transmitter PWA
The CIG transmitter PWA contains one red LED that is driven by the CIG receiver
PWA as part of synchronous break-beam detection system. The light from the CIG
transmitter shines across both CIG receiver sensors, which are located at the front
and back of the lower gripper jaw.