Model 625/630/632
Can I generate analog waveforms and a separate phased-locked digital signal or trigger? The 625A stores both analog waveforms and digital waveforms in separate memories. In this way, it is possible to store an analog waveform for presentation at the SIG OUT connector and a digital signal for presentation at the SYNC OUT connector. When both waveforms have the same length, the signals are phase-locked. One could use the SYNC OUT for a trigger or multiple triggers. (Back)
Can I obtain two outputs from one Model 625? The SYNC OUT is a TTL, fixed transition time, fixed amplitude signal. The SIG OUT provides variable levels and multiple signals that are available from the 625A. (Back)
Can I get Square Wave and Sine Wave together? When the SIG OUT is providing sine waves, the SYNC OUT provides a signal that is high when the sine wave is positive and low when the sine wave is negative. (Back)
How do the two output pulses differ in the Pulse Generator mode? In the Pulse Generator Mode, both the SIG OUT and SYNC OUT provide pulses that are identical in time. The SIG OUT allows variation of the level; the SYNC OUT is fixed. (Back)
Is there a Trigger Output for Functions and Sweep modes? The SYNC OUT provides a high going pulse at the beginning of a sweep and function. (Back)
What is the External Modulation In connector used for? This rear panel connector can be used to insert modulation signals onto a carrier. In conjunction with modes such as AM, FM, SSB, Ext Mod can even provide communication signals at the SIG OUT connector. (Back)
How does DTMF Detect mode work? Signals inserted into the External Modulation In connector are interpreted and the results displayed on the 625A”s front panel and sent to the RS232 port. (Back)
How does the Model 625 measure Power Level and Voltage? The signal at the External Modulation In connector are measured and the results displayed on the 625A”s front panel and sent to the RS232 port. (Back)
How do I Gate the signals out of the Model 625? A rear panel External Trig/Gate/FSK/BPSK input enables a digital signal to gate most modes of operation. (Back)
How do I Trigger Bursts and Sweeps? This is done via the rear panel External Trig/Gate/FSK/BPSK connector. (Back)
How do I obtain FSK and BPSK modulation? Digital data from the rear panel External Trig/Gate/FSK/BPSK connector is the modulation source. (Back)
Can I use an External Arb clock? The rear panel Input/Ext Arb clock connector is where your clock is inserted. (Back)
Is it possible to phase lock several Model 625‘s? In the Arb mode, you can tie the common reset times and common clock sources together. The waveforms need not be identical; just the length of the waveforms. (Back)
Can the Model 625A signal generator generate digital QAM signals? It depends on your constellation. If you desire to generate MPSK, then one unit can provide a baseband modulating signal to another that is operating in external phase modulation mode. If your QAM constellation involves amplitude and phase modulation, then you can use two units locked together; one generates the I baseband channel and the other generates the Q baseband channel. You would then need to feed these two signals to a quadrature modulator (external). (Back)
How can we provide a complex signal bit stream to the signal generator? Any user data would be downloaded from a host computer and stored in the arb memory. Any kind of zero-intersymbol-interference or spectral shaping filtering would be done mathematically on the PC before the download. (Back)
How do I generate an ECL signal with the Model 625A? With the 625A in the Pulse Generator Mode (function and pulse generator requires the ARB circuitry to operate), set the Offset at the midpoint of your desired signal. Set the Peak-Peak level for the desired swing. The Pulse Generator mode”s highest frequency is 2 MHz. If you need higher rates, insert a commodity TTL to ECL translator after the SYNC OUT signal. (Back)
How soon after the end of a waveform can the next trigger take place? A single Arbitrary Waveform is triggered by the External Trigger. You must wait one data point after your waveform concludes. To help you determine when the last data point of your waveform occurs, use the SYNC OUT, which has its own set of Arbitrary data points, as an indicator of the last data bit. That shortest pause is equivalent to your sample period. (Back)
What happens if an External Trigger occurs during the coarse of an Aribitrary Waveform? The trigger is ignored and only after entire Arbitrary Waveform is over, does the next trigger start the waveform again (Back)
