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Publication No. 980938 Rev. K
Model T940 User Manual
Astronics Test Systems
Introduction 1-9
Power Converter (PC)
The PC may be optionally installed on the Digital Board when variable voltage
DR boards such as the DR3e, DR9, or UR14 are used. The PC converts
backplane voltages into digital bias voltages. Its protection circuitry can detect
faults in any of the four on-board power supplies, status of the input fuses, or a
high input current or overcurrent condition. There are three types of power
converters, each of which has seven voltage ranges.
Digital Board (DB)
The DB contains the connectors and headers required for routing signals to/from
the VXI backplane as well as the DRA/DRB logic. The DB logic is comprised of
the following major components.
VXI Bridge
The VXI Bridge maintains the VXI interface with the backplane. The bridge
includes the communication registers for the VXI protocol requirements. The
DRM functions are programmed through VXI A16/A32/A24 register access.
Inter-Module Control
In a multi-module system, the VXI Local Bus is used to synchronize the modules.
The Inter-Module Control logic is used to route and terminate these signals.
Data Sequencer A and B
Each DB contains two Data Sequencers, DSA and DSB. Each data sequencer
can be run independently or synchronized. Data Sequencer A provides the
timing, memory and control for the DRA board (Channels 1 through 32). Data
Sequencer B provides the timing, memory and control for the DRB board
(Channels 33 through 64).
The Data Sequencer logic consists of the following:
•
Timing Data (Phase Assert, Phase Return, Window Open, Window Close)
•
Stimulus Format Code (Non Return, Return to Zero, etc.)
•
Pattern Data (Output Levels, Input Compare, CRC Enable)
•
Sequence Data (Pattern Period, Pattern Order, Looping, Conditional Testing)
•
Result Data (Error Flags, Error Count, CRC per Channel, Record Memory)
Driver/Receiver (DR) Board
Driver/Receiver Board A (DRA)
The DRA board contains all the driver/receiver logic, relays, sensors and
termination circuitry for channels 1 through 32.