RS232 remote control host program

An example program written in Basic to remotely control the 625. It also illustrates how DTMF digits detected by the 625 can be sent to and processed by the host computer.

Television remote control host program

An example program to remotely control the 625 in Burst mode. The 625 drives an infrared LED to emulate a television remote control transmitter.

LabView Driver

One of our customers has submitted a LabView Driver for the 625. He describes it below: Attached is a LabView v4.1 .LLB file containing 3 vi's (virtual instruments). Converse w/625, freq&dbm and scanMhz. It presumes COM1 and that the port has been initialized before running converse as this type initialization is typically done globally. It works just fine and is quite happy controlling the 625... What I am doing here is using LabView to control the 625 and then using my Fluke99 Scopemeter to record the outputs of the circuit. I have a voltage & current setup with a 10ohm shunt in the ground that lets me do vector impedance measurements with the scope. I can also do FFT and other trick math on the waveform using LabView. It really is quite slick. Charles Krinke Newport Beach, CA

LabView v4.1 .LLB file - Downloads 625.LLB to your machine.

Comb (Multitone) Generator

Another of our customers needed to generate a comb signal consisting of up to 200 sinusoids spaced at regular frequency intervals for amplifier testing. The program below calculates a composite waveform consisting of the tones. The user may enter the number of tones, starting frequency, and spacing between the tones. The resulting waveform may be sent directly to the 625 over the serial port or saved to disk.

Multitone Generation Program - Download TONES.BAS to your machine.

This file is the source code to the Multitone Generator program written in Microsoft Quickbasic.

The 625 may be used to generate a useful sinewave and squarewave output to about 22.3 MHz. Simply switch the unit to Internal SSB mode and set the modulation sideband to Upper. The output frequency is the sum of the modulation frequency and the carrier frequency. Since the modulation frequency can be set as high as 5 MHz, output frequencies up to 25 MHz may be specified. (However, internal filtering limits the useful output to about 22.3 MHz.) Data Acquisition Instrument

The 625 has a voltage and power measurement mode which will send the measured data to a host computer over the RS232 port. The 625 may therefore be used to periodically measure an externally applied signal for data logging, feedback control, etc.

In the Voltage & Power measurement mode, the sine/square wave generator is still active. This means that you may use both the generator and the measurement functions of the instrument simultaneously. When the unit is switched to measurement mode, the instrument will continue to generate whatever output frequency and level that was last specified. A filter or other frequency selective circuit may be automatically characterized by setting an output frequency and level and then measuring the response. Under the control of a host program, a simple magnitude-only network analyzer may be implemented. Very low frequency (VLF) function generator with extreme resolution

Ie. 6.25 microhertz to 2500 Hz with 6.25 microhertz resolution!

The function generator in the 625A uses the arbitrary waveform generator system to generate the function generator waveforms. This results in precise, repeatable, and stable function generator waveforms. It also means that you can use the Arbitrary Waveform Generator to precisely control the sample clock. To do this, first switch the unit to Function Generator mode and select a function waveform (sine, square, triangle, etc). Next, set the waveform repetition rate to 1 Hz. (This fills the Arb waveform memory with 16,000 points of the desired waveform.) Now you may switch the unit to Arbitrary Waveform Mode and set a precise sample clock frequency (from DC to 40 MHz in .01 Hz steps). The function repetition rate is then given by:

Rep Rate = Sample Clock Frequency / 16,000 Multiphase AC Source
Quadrature (I and Q) Local Oscillator Generation
Phase Detector Characterization

Two or more 625A's may be locked together to generate multiple waveforms which are locked together in frequency. Each waveform may have its own phase offet from 0 to 359.99 degrees in .01 degree steps. This application is quite useful for multiphase AC power generation. Waveforms for 3 phase voltage and current may be generated to simulate any conduction angle for complex AC source/load simulation.

Communication engineers may use this feature to generate I and Q (90 degrees) local oscillators for QAM modulation and demodulation. By adjusting the phase, engineers may perform a phase sensitivity study of a communication system.

Phase detectors may also be fully characterized by adjusting the relative phase between two locked generators. With precise .01 degree steps over the full 360 degree range, a complete phase transfer curve may be determined. FM Radio Testing/Alignment (DC-140 MHz)

The 625 has a SYNC output which is a squarewave version of the sinewave output. This output has extremely fast rise and fall times and therefore has strong harmonic content. You may use the 7th harmonic of this output to generate modulated or unmodulated carriers to 140 MHz. Simply attach an antenna (or a short piece of wire will do) to the sync output and tune the FM radio to the desired station. Now set the 625 to FM modulation mode and enter the carrier frequency dividend by 7. For example, to transmit on FM station 97.3, you would set the carrier frequency on the SG-100 to 97.3/7= 13.9 MHz. You may use the Internal FM or External FM modulation modes to transmit a tone, voice, music, etc on that station. You may take advantage of the extreme accuracy and stability of the 625 to align filters, local oscillators, matching circuits and resonators using this same technique. And because the SG-100 uses a precise, second synthesizer for the modulating waveform, the discriminator/demodulator stage of the receiver may be accurately characterized. Adjustable Delay Generator

The 625 may be used to generate delayed trigger signals using the burst mode of operation. Delays from 1 ms to 99.999 sec may be generated with 1 ms resolution. To use this feature, switch the 625 to burst mode and select the triggered mode of operation. Next enter the desired delay and the delay field. You may then trigger the unit from the front panel, external trigger logic input or the R5232 port. Longer or shorter delays with greater resolution in time may be performed by using the function and arbitrary waveform generators together. Variable Bandwidth Noise Generator

The 625A function generator includes a noise waveform as one of its standard functions. The noise waveform is generated by filling the arbitrary waveform memory with random samples. The function generator has a rep rate field which determines how often the generator repeats the buffer of random samples. A precise method of controlling the sample rate is to use the Arbitrary Waveform generator. First switch the unit to Function Generator mode and select “random” as the desired waveform. Next, set the waveform repetition rate to 1 Hz. (This fills the Arbitrary waveform memory with the maximum number (16,000) of random samples. Now switch the unit to Arbitrary Waveform mode and directly enter a sample clock frequency, from .01 Hz to 40 MHz in .01 Hz steps. In this way you may control the bandwidth of the noise generator from DC to 10 MHz. (The 10 MHz limit is due to an internal 10 MHz low pass filter on the output of the Arb D/A converter).

Telephone Network Call Progress Tone Generator

The 625's new Dualtone Generation Mode may be used to generate all of the common signaling waveforms used in the American and other telephone Networks. The Dualtone Generation mode adds two sinusoids together of any frequency between DC and 10 KHz. The frequency of each tone may be independently specified with 1 Hz resolution. In addition, the resultant output waveform may be continuous or turned on and off with any specified ON time and OFF time between 1 mS and 10.000 Seconds. By switching the 625 to Dualtone Generation Mode and entering the parameters in the table below, the following call progress tones may be generated:

Name	Frequency 1	Frequency 2	On Time	Off Time
Dial Tone	350 Hz	440 Hz	1 mS	0 mS
Ringback	440 Hz	480 Hz	2,000 mS	4,000 mS
Busy	480 Hz	620 Hz	500 mS	500 mS
Reorder	480 Hz	620 Hz	250 mS	250 mS
DSN Preempt	440 Hz	620 Hz	1 mS	0 mS
European	420 Hz	440 Hz	various	various

FDA Susceptability Testing

One of our customers needed a signal source which performed a 1,000 second sweep between two frequencies while AM modulating at 80% modulation. The customer applies this signal to a power amplifier and transmitting antenna to certify their new medical product against a MIL standard susceptability requirement.

To meet this need, we wrote the following program which steps the 625 carrier frequency in Internal AM mode. In the program, the user may adjust all parameters: sweep frequencies, time, AM modulation frequency and depth. This program demonstrates how a simple control program can greatly enhance the versatility of the 625.

FDA Certification Program - Download FDA.BAS to your machine.

This file is the source code to the FDA control program written in Microsoft Quickbasic.

Audio Pitch Shifter

The 625 can be used to upshift the frequency spectrum of an audio signal. Simply apply the audio signal to the External Modulation In Connector. Attach a speaker or other listening device to the SIG OUT connector. Next set the 625 for External Single Sideband (Ext SSB) mode and select Upper Sideband. Now you can specify any amount of frequency upshift by adjusting the carrier frequency, from 0 Hz to 21.5 MHz in .01 Hz steps!

DC Voltage Source

By setting the output frequency to 0 Hz, the 625 may be used as a variable DC voltage source by adjusting the output offset. You may generate from -12.0V to +12.0V in 1 mV steps. The output impedance of the source is 50 ohms.

Digital Clock Source with "Jitter"

The SG-100 may be used to generate a digital clock with phase or frequency "jitter." This can be useful for testing the tracking capability of a Digital Phase Locked Loop (DPLL). The TTL/CMOS output is used while in FM mode. Set the carrier frequency to the desired clock center frequency and adjust the modulation rate and deviation to achieve the desired clock "jitter."

Rife Generator Pulsed Wave Shaper

Several of our customers are using the 625A to generate high energy pulsed waveforms which are said to have healing effects. This program generates a square waveform which has an exponentially modulated amplitude envelope. By shaping the envelope of the pulse waveform, the healing effects may be increased. The program presents a menu which allows adjustment of many parameters, including envelope shape. The waveforms may be downloaded directly to the instrument or saved to disk file.

Rife Generator Program - Download EXPWAVE.BAS to your machine.

This file is the source code to the exponential waveshape program written in Microsoft Quickbasic.

Sweep with Instantaneous Frequency Display

This program perform a sweep by incrementing the frequency in Sinewave mode at regular intervals using the RS232 port. The instantaneous sweep frequency is displayed on the screen. The program presents a menu from which you may enter start freq, stop freq, sweep time, and level. In addition, the sweep may be paused, reversed, or restarted so that you may iteratively hone the sweep to focus on a frequency band of interest.

Sweep Menu Program - Download SWEEP.BAS to your machine.

This file is the source code to the exponential waveshape program written in Microsoft Quickbasic.