Arbitrary/function generators focus on sweep and modulation facilities

July 25, 2014 // By Graham Prophet
The Yokogawa FG400 Series is a range of arbitrary/function generators that combine intuitive operation with comprehensive sweep and modulation facilities. The instruments allow the creation of basic, application specific and arbitrary waveforms, and have isolated output channels which allows their use in the development of floating circuits in power electronics applications.

The range consists of two models: the single-channel FG410 and the two-channel FG420: both generating signals of up to 20V peak-to-peak over the frequency range 0.01 µHz to 30 MHz. Operation is via front-panel pushbuttons and a 3.5-in. LCD screen which displays alphanumeric values alongside the generated waveforms.

The instruments incorporate a number of basic waveforms as standard, including sine, DC, ramp, square and pulse. Advanced functions include sweep (frequency, phase, amplitude, DC offset and duty), modulation (FM, FSK, PM, PSK, AM, DC offset and PWM) and burst (auto, trigger, gate and triggered gate).

Up to 128 arbitrary waveforms of up to 512 kwords per waveform can be generated and saved to the instrument's internal non-volatile memory, and can then be selected from a displayed list. The waveforms can be created in the FG400 or with the free editing software supplied. Sequences of different waveform patterns can be generated and edited by programming the appropriate parameters.

The FG400 Series can also generate arbitrary waveforms based on signals that have been acquired by measuring instruments. Troubleshooting is made easier as the instrument can then generate waveforms that are difficult to reproduce, such as noise that only occurs on-site. With the editing software, waveforms that are acquired using a Yokogawa DL850E ScopeCorder or DLM4000 mixed-signal oscilloscope, for example, can be analysed on a PC to find the abnormal waveform. This abnormal part can then be clipped, saved and generated using the FG400.

The FG400 Series also provides 25 different types of application-specific waveforms including those needed to evaluate the response characteristics of mechanical/electrical circuits and to emulate power supply circuits. As the parameters of these application-specific waveforms can be changed like those of basic waveforms, waveforms are quicker and easier to generate.