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 home > Services > Telemetry and Data Systems > Recorders and Multiplexers > Rackmount > PCM Simulator/Encoder VSIM/ENC-950
Features
• Tunable rates to 20 Mbps
• Programmable NRZ-L/M/S, BI?-L/M/S, DM-M/S, and RNRZ-L PCM Codes
• Programmable SFID, FCC, URC Subframe Structure
• Any Combination Sub- and Super-commutation
Introduction
The dynamic PCM Simulator/Encoder board (VSIM/ENC-950) is a full, IRIG Class II, stand-alone PCM module. The VSIM/ENC-950 board fits into a single VME 6U slot with all external signals available to the user on the front panel for easy access. The PCM Simulator/Encoder is a powerful tool that is useful for system test and checkout as well as a means of generating a true PCM stream to be used for sending information to another data acquisition platform or test system.
The PCM Simulator/Encoder has two modes of operation: single CVT encoder or double-buffered CVT buffer. In the single CVT encoder mode, the host loads the instruction sequencer with the format of the frame of data to output and then loads the CVT with parameter values to output. Once the simulator is enabled to run, it pulls data from the same CVT locations each time through the sequencer instructions. A FIFO may also be used as a source of data for message type formats with fill inserted when the FIFO is empty.
In the double-buffered CVT mode the sequencer is loaded the same way, but the CVT is divided into two equal halves. The sequencer reads from the first CVT until a cycle bit is detected. If the other half of the CVT is updated it, can start outputting from this half. The FIFO can also be used as a source of data in this mode. Data in the CVT may be updated at any time without interfering with the output stream. An interrupt can be generated on any word in the PCM output stream. By setting the STOP bit the PCM stream can be halted until the user disables it.
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Input
Clock
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Clock Source
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Internal or external
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Clock Rate
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1 kHz to 20 MHz (down to 1 Hz, external)
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External Clock Input
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TTL, 75 ohms
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Output Data
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PCM Codes
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Programmable NRZ-L/M/S, BiÆ-L/ M/S, DM-M/S, RNRZ-L
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(forward and reverse, lengths 9,11, 15)
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Rate
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1 Kbps to 20 Mbps, NRZ codes
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500 bps to 10 Mbps all other codes
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Polarity
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Normal or inverted per format
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Level
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TTL compatible (single-ended) into 75 ohm load &
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RS-422 differential
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Frame
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Major Frame Size
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Programmable up to 1,000,000 word locations
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Word Size
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4 To 32 Bits, programmable
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Words per Minor Frame
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1 to 250,000, programmable
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Frames per Major Frame
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1 to 65,536 minor frames, programmable
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Frame Sync Length
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4 to 64 bits, programmable
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Subframe Sync Method
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None, SFID, URC, FCC; up to 16 bits
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Flat CVT Size
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64K parameters (32 bits per parameter)
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Double-Buffer CVT Size
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32K parameters per buffer
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Supercom and Subcom
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Any combination of word locations
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FIFO Size
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1K parameters with programmable fill word
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when data not present
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Encoder
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Source of Input Data
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Real-time system parameters
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Processing
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Control
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Full VME compliant interrupts
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Data Flow
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CVT, or FIFO, single or double-buffered frames
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Output
Clock
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Type
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Coherent with NRZ-L data output
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Clock Phase
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Programmable 0 and 180 degrees
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Level
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TTL compatible into 75 ohm load
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Electrical and
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Form Factor
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6U Versa Module Europe (VME),
single slot
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Environmental
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Connectors
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BNC: TTL, programmable PCM data, and 180° clock
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output, external clock input
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DB9: RS-422, 180°
clock, programmable PCM data
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DB25: TTL, programmable PCM data (x5), 0° clock, and 180° clock outputs; external clock input
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Temperature
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0 °C to 50 °C operating; -20 °C to 80 °C storage
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Humidity
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20 to 95% noncondensing
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Ordering Codes
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VSIM/ENC-950
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Advanced Simulator/Encoder
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