This synthesized programmable function generator has the following features: • Sinewaves up to 40MHz, squarewaves up to 50MHz • 11 standard waveforms available plus pulse and arbitrary • User defined pulses and pulse trains with 10ns resolution • Arbitrary waveforms up to 100MHz sampling frequency • Up to 4 arbitrary waveforms of 4 to 64k points with 12 bit vertical resolution • Triggering, summing and modulation of all output waveforms • RS232 and USB and optional GPIB interfaces The instrument uses a combination of direct digital synthesis and variable clock techniques to provide high performance and extensive facilities in a compact instrument. It can generate a wide variety of waveforms between 0·1mHz and 50MHz with high resolution and accuracy. Arbitrary waveforms may be played back with 12 bit vertical resolution and from 4 to 65536 horizontal points. All waveforms can be swept over their full frequency range at a rate variable between 1 millisecond and 15 minutes. Sweep can be linear or logarithmic, single or continuous. Single sweeps can be triggered from the front panel, the trigger input, or the digital interfaces. A sweep marker is provided. Amplitude Modulation is available for all waveforms and is controlled from an external generator via the MODULATION input socket. Signal Summing is available for all waveforms and is controlled from an external generator via the SUM input socket. All waveforms are available as a Triggered Burst whereby each active edge of the trigger signal will produce one burst of the carrier. The number of cycles in the burst can be set between 1 and 1048575. The Gated mode turns the output signal On when the gating signal is true and Off when it is false. Both Triggered and Gated modes can be operated from the internal Trigger Generator (0.005Hz to 100kHz), from an external source (dc to 1MHz) or by a key press or remote command. The signals from the REF IN/OUT socket and the SYNC OUT socket can be used to phase lock two instruments. This can be used to generate multi−phase waveforms or locked waveforms of different frequencies. The generator parameters are clearly displayed on a back lite LCD with 4 rows of 20 characters. Soft−keys and sub menus are used to guide the user through even the most complex functions. All parameters can be entered directly from the numeric keypad. Alternatively most parameters can be incremented or decremented using the rotary control. This system combines quick and easy numeric data entry with quasi−analogue adjustment when required. The generator has RS232 and USB interfaces as standard which can be used for remote control of all of the instrument functions or for the down−loading of arbitrary waveforms. As well as operating in conventional RS232 mode the serial interface can also be used in addressable mode whereby up to 32 instruments can be linked to a single PC serial port. There is also a GPIB option.