User's Manual

UMAC CPCI Accessory Cx Family
Introduction 1
INTRODUCTION
The Acc-Cx family of backplane boards for the UMAC CPCI controller provides the connection means
for field wiring, power supply and interboard communications for this controller. These backplane boards
implement the Compact UBUS communications bus that enables the UMAC CPCI CPU board to
communicate with the motion and I/O interface boards. The x in the accessory name refers to the number
of Compact UBUS slots (including the slot for the CPU) on the board.
For each 3U-format board installed in the backplane, there is also a pass-through connector on the
backplane board that permits a distribution system for the field wiring from the rear of the rack. With the
proper system engineering, this results in a very neat, hidden system of distribution wiring.
The Acc-Cx also provides the power-input connector and the power-supply installation connector for the
system.
The Acc-C8 8-slot Compact UBUS Backplane board (part number 300-603617-10x) was the first of this
family to be designed. Others may be available. Contact a Delta Tau distributor for details.
The Acc-C8 8-slot backplane board:
The Compact UBUS is a high-density version of Delta Tau’s UBUS backplane bus for the original
UMAC controller. Whereas the original UBUS utilizes a VME-style 96-pin DIN connector that occupies
the full height of a 3U-format board, the Compact UBUS uses a Compact PCI-style 110-pin high-density
connector that occupies only the bottom half of a 3U-format slot. The Compact UBUS is identical in
operation, both electrically and in software, to the original UBUS; only the form factor has changed.
While the Compact UBUS uses the same connections as the Compact PCI bus, and uses the same power-
supply and return pins, it is designed as a terminated bus, whereas the Compact PCI bus is un-terminated.
Every signal line on the Compact UBUS has a 330-ohm pull-up resistor at each end, and a 470-ohm pull-
down resister at each end.