Overview 1

Instrument Features and Capabilities

overflows (reaching the maximum count), the display briefly shows OL (overload) and begins counting from zero again

A totalizer input from contact closures increments on the “open” portion of the switch sequence close-open. To prevent switch contact “bounce” from triggering false readings, select the Totalizer Debounce feature. A totalizer input from voltage transitions increments during low-to-high voltage transitions with a nominal threshold of +1.4 volts. The maximum voltage input is +30V dc, and the minimum voltage input is -4.0V dc. The maximum totalizer rate is 5,000 transitions per second without debounce and 500 transitions per second with debounce.

The instrument reports Totalizer status with scan data and can display it at the front panel. You can clear the Totalizer count by cycling power to the instrument or via NetDAQ Logger.

Trigger Input

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Trigger Input is an instrument connection used to trigger scans from an external source. The connection uses the ALARM/TRIGGER I/O terminals TI and GND (Figure 1-4). A contact closure or logic low between TI and GND triggers an instrument scan if External Trigger is enabled. While the trigger input line is held low, the instrument continues to scan at Interval 2.

When there is no trigger input, an internal pull-up resistor holds the input at logic high (nominal +5.0V dc).

Trigger Output

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Trigger Output is an output line that, when enabled, goes to logic low for 125 µs every time a scan begins. The connection uses the ALARM/TRIGGER I/O terminals TO and GND (Figure 1-4). Use the Trigger Output to trigger other instruments by their Trigger Input connection and to interface with external equipment. An internal pull-up resistor holds the trigger output line at a logic high (nominal +5.0V dc) when there is no trigger output.

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Fluke 2640A, 2645A user manual Trigger Input, Trigger Output
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2645A, 2640A specifications

The Fluke 2640A and 2645A are advanced bench multimeters that represent a significant leap in measurement technology, designed primarily for electrical engineers and technicians who require precision and reliability in their readings. These multimeters are built to cater to complex applications in manufacturing, research, and development.

One of the standout features of the Fluke 2640A and 2645A is their high accuracy. With specifications that can reach up to 0.0035% DC Voltage accuracy, users can trust that their measurements will be consistent and precise. This is especially critical in fields like automated test equipment (ATE) where exact measurements can be crucial for product quality and safety.

Both models incorporate a large, easy-to-read display, making it convenient for users to view measurement results clearly from a distance. They also feature a wide measurement range, capable of handling a variety of tasks, from basic voltage and current measurements to more complex tasks such as resistance and temperature measurements with appropriate sensors.

The multimeters also stand out with their advanced data logging capabilities. The Fluke 2645A, for instance, can store up to 10,000 readings, allowing for extensive data collection and analysis without the need for constant monitoring. This is beneficial for long-term studies or processes that require continual oversight.

Connectivity is another key characteristic. Both the 2640A and 2645A support USB and RS-232 interfaces, which enable easy integration with computers and other devices for seamless data transfer. This feature is important for engineers who rely on software for data analysis and visualization.

Another notable technology included in these models is the Fluke Connect app compatibility, which allows users to remotely monitor measurements from their smartphones or tablets. This capability provides added flexibility, enabling technicians to work hands-free while still keeping an eye on process measurements.

Additionally, the Fluke 2645A comes with a graphical display option, allowing users to visualize measurement trends over time. This graphical representation can be invaluable for diagnosing issues or observing patterns in data.

In conclusion, the Fluke 2640A and 2645A multimeters offer exceptional performance with their high accuracy, extensive data logging, connectivity options, and advanced visualization capabilities. These features make them indispensable tools for professionals in a variety of fields, ensuring that they can achieve reliable results in their measurement endeavors.
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