Highland T560, Техническое руководство

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10 T560MANK5.DOCX
3. Overview of the T560
The T560-1 is an embedded digital delay/pulse generator. It accepts a trigger pulse and
generates up to four output pulses, with each pulse being individually programmable in
delay and width. Triggers may be external, internal, or evoked through the communications
interface. Timing has crystal-clock precision with picosecond jitter relative to an external
trigger.
Each output is user programmable for delay (0-10 seconds) and width (0-10 seconds) with
10 ps resolution. When externally triggered, all delays are relative to the basic 20 ns
insertion delay.
3.1. Standard Packaging
The standard T560-1 unit is packaged in a small extruded aluminum enclosure. The
Ethernet connector is provided on the T560-2 version. Section 7 of this manual provides
detailed dimensions.
3.2. Overall Block Diagram
Figure 3-1 T560 Basic Block Diagram is the block diagram of the T560-1. OEM versions
may include various features of the module. The optional Ethernet interface is not furnished
on the standard T560-1 version.
The T560 digital delay generator creates delays by digitally counting a basic clock to create
coarse delays to a resolution of 20 nanoseconds, and then adding a fine analog delay to
interpolate the final times to picosecond resolution. The timing clock is derived from a 50
MHz gated oscillator which is started when an internal or external trigger is received. A
DSP-based phaselock system digitizes and compares the waveforms generated by this
oscillator to that of a precision 10 MHz crystal oscillator and servoes the gated oscillator to
be as accurate as the crystal while still maintaining the timing relationship to the original
trigger.
The T560-1 supplies four TTL pulse outputs, each programmable in delay and width.
Custom versions of the T560 can provide up to eight independent delay outputs.
Because the all-digital phaselock system uses no drift-prone analog signal storage
elements, long-delay accuracy and jitter depend only in the quality of the internal or
external 10 MHz timebase.