Sync Box DC-in io

MCE0 to MCE7

8 Fibre outputs. Carries a 50 MHz Manchester-encoded signal containing data packets, which include incremented sequence numbers. Programmable as two sets of 4 outputs with differently spaced data packets on each.

RS232 Command IO

DB9 connector, TTL input and output, used to command the Sync Box from a PC using a regular RS232 cable.

TTL-IN

BNC connector, TTL input, spare input to the FPGA. ***Not currently used, and open for suggestions.

TTL-OUT

BNC connector, TTL output. Carries a 50 MHz clock signal.

Interface Connector

A DB25 connector that provides the following auxiliary input/outputs:

Data Valid

TTL input. Detects falling edges from a Real-Time Sequencer (implemented by SCUBA2) which tells the Sync box when to tell the MCE's to collect data.

OPTO-TTL

TTL input, spare input to the command processor. ***Not currently used, and open for suggestions.

DATA_SYNC1 (formerly DV_SPARE1)

TTL output. Carries a 5 MHz clock signal that is synchronous with DATA_SYNC2. (WARNING: signal polarity may be swapped)

DATA_SYNC2 (formerly DV_SPARE2)

TTL output. Carries a 5 MHz data signal that is synchronized with DATA_SYNC1, and contains the same frame sequence numbers as the MCE(0-7) outputs. NOTE: This output only contains the DV info stream (40-bit), but not the occurrences of Addr_Return-to-Zero between DVs. (WARNING: signal polarity may be swapped)

DATA_SYNC3

TTL output. asserted for 1us on an Address-Return-to-Zero(ARZ) if a DV pulse is detected since the last ARZ.

DATA_SYNC4

TTL output. asserted for 1us on an Address-Return-to-Zero(ARZ) if a DV pulse is detected since the last ARZ.

Connector Pinout

Block Diagram

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