The Model 1391 is a 1 mHz to 50 MHz "C" size VXI Programmable Pulse Generator. It can generate single, double, and delayed pulses with programmable period, width, delay, rise/fall transitions, and output levels. The generator operates as a continuous, triggered, gated or burst pulse source up to 50 MHz. Additionally, the Model 1391 can be programmed for a square wave function (*50% time symmetry) up to 100 MHz. Pulse characteristics are programmable with 4 digit resolution, with width and delay up to 2000 seconds, and rise/fall transition times settable from 5 ns to 50 |is. The pulse ouput amplitude may be specified as upper and lower levels, which can be programmed in a ±16 V window (±8V into 50Q termination). Peak to peak amplitude, upper level value minus lower level value, is continuously variable in 10 mV steps from 150 mVp-p to 16 Vp-p (50Q). The pulse amplitude (upper, lower, or both) may be modulated (PAM) with an external signal. Control of the pulse generator adheres to the SCPI (Standard Commands for Programmable Instruments) format Version 1.0, April 1990 (refer to the SCPI manual for further information). SCPI is an industry standard language for remote instrument programming. Using any manufacturer's VXI chassis, the Model 1391 can be controlled using the SCPI language and the appropriate controller. Multiple pulse generators may be linked and operated together inside one VXIbus chassis. Series operation is provided by full support of the VXIbus SUMBUS. A signal programmed at the output may be sent to the SUMBUS, or signal present at the SUMBUS may be summed into the model 1391 output. In parallel operation, model 1391 *s may be slaved to a master clock/trigger bus on the VXIbus backplane to create a multichannel pulse generator. The model 1391 has extensive self-adjustment utilities built in. Calibration constants are maintained in nonvolatile memory. 1.2 Specifications 1.2.1 Functions Programmable single, double or delayed pulse and fixed («50%) duty cycle square wave. 1.2.2 Operating Modes Continuous: Pulse period generated continuously internal to the model 1391 at programmed frequency/period. Selected pulse waveform is continuously output at PULSE OUT with programmed pulse characteristics. Period timing signal appears at SYNC OUT (if enabled) and may be selected for output to the backplane. Pulse periods programmable up to 25 MHz in double pulse, 50 MHz in single or delayed pulse, and 100 MHz in square wave. Pulse Amplitude Modulation may be enabled for external signal at PAM IN. Triggered: As above for Continuous mode, except that pulse period generation is disabled. Output quiescent until triggered by an external signal at TRIG IN, a TTLTRG or ECLTRG signal, internal trigger frequency, or a VXIbus command, then generates one pulse period with the programmed pulse waveform and pulse characteristics. Triggered pulse periods operate to 25 MHz in double pulse, 50 MHz in single or delayed pulse and square wave. Gated: Similar to triggered mode except output continues for the duration of gate signal. The last pulse period started is completed. Burst: Similar to triggered mode except programmable number of pulse periods in a burst. Burst length, initiated by the trigger signal, is programmable between 2 and 1,000,000 cycles.