kHz-SLR PC Board

Eastbourne,

October 2005for kHz SLR

Complete PC Board

Motivation

Eastbourne, October 2005

Present kHz Setup at Graz: Runs nearly perfect, very stable, reliable (DOS ...) It is simple to operate; Lot of space for additional software routines; etc. etc.

BUT: Not easy to add new hardware, controls, cables ... Needs „drilling holes“ to add simple new features ... Limits on available I/O lines on present FPGA chip; „Provisional“ or „Grown“ hardware: Eliminate it ...

=> Decision made to design a new kHz Control Board

Design Goals

Eastbourne, October 2005

This kHz SLR PC Board should Handle / control all common tasks in kHz SLR; Be flexible, easily adaptable for future tasks; Be easy to program, with any language;

In other words: It should be a

Simple, Modular, Inexpensive Laser Equipment

==> „SMILE“

(And due to kHz ==> it‘s a „kilo-SMILE“ )

Design

Eastbourne, October 2005

Design of the kHz PC Board:

Simple ISA Board, fits in any PC with ISA slots; Industry boards with 3-GHz PC cards available; The board contains mainly

a big FPGA (Field Programmable Gate Array), Interface to the PC; plus some glue electronics;

About 150 I/O lines available; With additional, cheap A/D converter card, the

complete Graz kHz SLR station can be operated; ISA cards are plugged into standard passive backplane

Features implemented (1)

Eastbourne, October 2005

1 pps and 10 MHz applied; Generates internal time scale, 1 µs resolution; Internal Time Synchronized to UTC / GPS; Allows access to actual time within few µs ...

Complete Range Gate Generator 0.5 ns Resolution, < 1 ns accuracy; Internal FIFO registers for up to 300 next gates (GPS); Just program next RG event time, and forget it

Features implemented (2)

Eastbourne, October 2005

Complete kHz Laser Control: Generation of Laser firing triggers (10 Hz – 2 kHz); Control of Pump Diodes for the kHz Laser (CW) Control and/or Dephasing of Amplifier Pump Diodes:

Allows simple attenuation for Calibration etc. Handles safety inputs from Aircraft Detection etc.

Handles communication with Event Timer(s): Graz E.T.; Riga E.T.; future ETs ? Asynchronous Read-Out of Event Timers;

Features implemented (3)

Eastbourne, October 2005

Automatic Receive/Transmit Overlap Avoidance Automatically detects such situations; Shifts next Laser Firing pulses accordingly; No external checks / no intervention necessary; Saves considerable CPU time of Real Time PC ...

Serial 64-Bit Interfaces (I/O); several units: Single BNC cables to Mount, Laser, Observers ... 64-bit words transmitted / received serially; Each bit controls mirrors, switches, FOV, DIV, etc.... Very flexible / upgradable, just add a line in programs

Status of kHz SLR board

Eastbourne, October 2005

First prototype is operational:

All functions / subroutines tested, verified; Plugged into passive backplane; Together with a standard 3.2 GHz CPU board; Main kHz programs will be adapted within next weeks;

Image of Graz kHz SLR Board