Triggering the Digitizers

This section describes digitizer triggering, including:

•Trigger Sources

•Using Internal Triggering

•Using External Triggering

•Master/Slave Operation

Trigger Sources Triggering digitizer readings across all input channels is accomplished with one or both of the two trigger sources (TRIGger:SOURce1 and TRIGger:SOURce2). The trigger event can be different for each source. For example, SOURce1 can be EXT and SOURce2 can be TTLT0. Use TRIG:SOURce<n> to set the trigger source event options which can be OFF BUS EXT HOLD IMMEDIATE INTernal1-4 TTLT0-7.

You must execute TRIG:SOURce<n> two times to set both trigger sources (TRIG:SOUR1 and TRIG:SOUR2). At power-up and after resetting the module with *RST, TRIG:SOUR1 defaults to IMM and TRIG:SOUR2 defaults to HOLD. The number of readings set by SAMPle:COUNt are taken after the trigger event occurs.

NOTE Do not confuse TRIG:SOUR1 as being associated with only channel 1 (as well as TRIG:SOUR2 with only channel 2). Both sources are common to ALL channels and the “1” and “2” are not channel designators but “source” designators.

Using Internal Triggering

Using SCPI or VXIplug&play, you can trigger internally from a voltage level from any channel. The trigger level is set using TRIG:LEVel<channel> <voltage> for the channel you want to generate the trigger event. You then set the trigger source to trigger internally from that channel using TRIG:SOURce<n> INT<channel>. For example, to trigger from a 11.5V level on channel 2, send VOLT2:RANG 16; TRIG:LEV2 11.5; TRIG:SOUR INT2. Figure 2-1 shows the relationship of the trigger level to the internal trigger source.

Each channel has a level compare circuit that compares the input signal to the value set by the TRIG:LEVel<channel> command. This level initiates a trigger when the input signal equals or exceeds the value set by TRIG:LEVel This means the trigger can occur at a value other than the value set by the TRIG:LEVel command.

For example, assume a trigger level of 0V on a ramp from -1V to +1V. The first samples may be negative values close to zero. These values will not cause a trigger because they do not equal or exceed the trigger level value yet. The next sample may be a positive value greater than the trigger level. The trigger compare circuit (see Figure 2-4) detects this level is equal to or greater than the trigger level value set and a trigger is generated.

It was not, however, generated at the exact trigger level value set by the TRIG:LEVel command.

Chapter 2

Using the Digitizers 37

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Agilent Technologies E1563A, E1564A user manual Triggering the Digitizers, Using Internal Triggering
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E1563A, E1564A specifications

Agilent Technologies, a prominent player in the field of electronic measurement, offers a range of products designed for various testing applications. Among their notable offerings are the E1564A and E1563A modules. Both models are designed for high-performance testing and measurement, catering particularly to the needs of engineers and technicians in the telecommunications and wireless industries.

The Agilent E1564A is a high-speed data and synchronization generation module, specifically tailored for advanced signal analysis. One of its primary features is its ability to provide a wide range of modulation types, including QPSK and 16QAM, which are essential for testing modern communication systems. The module also boasts a flexible output that supports multiple channels, making it efficient for testing complex systems where multiple data streams are present. Its exceptional performance in generating accurate waveforms enables engineers to perform thorough tests and validations on their devices.

On the other hand, the E1563A module is predominantly focused on protocol analysis and provides engineers with insights into the behavior of their communication systems. This module features comprehensive support for various communication protocols, making it invaluable when debugging and validating designs. Engineers can utilize the extensive measurement capabilities of the E1563A to analyze data integrity and system performance, ensuring that their products meet required specifications.

Both modules leverage advanced technologies from Agilent, ensuring high accuracy and reliability in measurements. They are equipped with powerful processing capabilities that allow for real-time data analysis, a critical aspect when working with high-frequency signals. Furthermore, these modules are designed for seamless integration into Agilent’s test and measurement platforms, enhancing usability and facilitating complex testing scenarios.

In summary, the Agilent E1564A and E1563A modules represent cutting-edge solutions for engineers involved in testing and validating communication systems. With their robust features, including support for various modulation schemes and protocol analysis, these modules enable efficient and accurate measurements. The commitment to quality and precision from Agilent Technologies continues to make these devices essential tools in the industry, helping engineers push the boundaries of innovation in telecommunications.
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