The DESY II system is a 19” rack mount system designed for laboratory environments. The DESY II is also available in a “Rugged” configuration for harsher environments. The rugged platform is not intended for extreme environments, but environments where vibration is present.

The DESY II is a high speed digital recorder and playback unit. It is controlled remotely using a subset of DCRsi commands from a host processor via RS-232 serial input, or it can function in standalone mode with monitor, keyboard and mouse. In standalone mode the DESY II is controlled with serial commands or a simple graphical user interface (GUI) control.

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Features

• The DESY II lab unit and DESY II rugged unit are high speed PC/RAID-based digital recorders.
• The DESY II system can record and playback data at any data rate from 0 to 30 megabytes/sec.
• The DESY II system is controlled using DCRsi commands and, when appropriate, responds in a like manner.
• The DESY II is also controlled using a simple graphical user interface.
• The DESY II is a PC based system with a RAID system for data storage. In a RAID 5 configuration, the DESY II removable RAID drives provide sequential storage with data striping at the byte level and stripe error correction information. This results in excellent performance and fault tolerance.

Parameter	Specification
Data Rate	0 to 30 MB/sec continuous 37.5 MB/sec burst Note: Higher throughputs (between 37MB/s to 46MB/s) have been demonstrated during acceptance testing.
Auxiliary Data	Not Supported
High Speed Data Interface	Byte wide, ECL differential
Addressable block size	4356 bytes
Control and Status Interface	RS-232 or RS-422
Error Rate	1/10/2014
Error Correction	ECC
Tape Transport
Type	Random Access (RA) or Rotary Transverse Emulation Mode (RTEM)
Tape Speed	RA = None RTEM = 5.9 ips
Shuttle Speed	RA = None RTEM = 88 ips (FF or RW) CAVEAT: The DESY II file system (Windows NTFS) provides random access to the files on the RAID. Seek times attributable to tape movement do not exist. However, to emulate the indexing, display, and locate functions of a tape machine RTEM mode exists. NOTE: The user is not required to operate the DESY II in RTEM mode. Random Access mode eliminates the time overhead of fast forward, rewind operations. and other seek operations.
Internal Time Code Resolution	+/-1 microsecond

Data Interface

The data interface is an 8-bit wide parallel interface with 8 parallel data lines, a common clock and one enable signal. Input and Output signals are ECL differential.

Variable Data Rate

The DESY II supports variable data rate recording from 0 MB/s to 30 MB/s. The DESY II adjusts to the input clock and records and plays at the input clock data rates continuously, or with fluctuating input, or in burst up to 37.5 MB/s. The DESY II's instantaneous recording and playback provides data capture without time delays associated with transport mechanisms.

Control Interface

An RS-232 or RS-422 serial interface controls the DESY II from a remote host. This interface controls the operation of the system, built-in-test, status and diagnostic reporting.

Transverse Scanning

The DESY II has a limited "Rotary Transverse Emulation Mode (RTEM)" of operation. This mode of operation is to support users and applications previously supported by digital tape recorders with rotary transverse tape transports. NOTE: Because the DESY II does not record to a tape, limited head life and head replacement are no longer issues.

Tape Cartridge Emulation

The DESY II does not use physical tape cartridges. It is a disk based digital data recorder which replaces the "tape cartridge" by segmenting the RAID drives into four partitions of approximately 50 gigabytes each. Each partition represents a tape cartridge of 50GBs or greater and is called a "Tape".