Appendix E

Binary Upload of Logged Data (LOG_BIN?) (2625A only)

Introduction

The LOG_BIN? <index> query can be used to quickly upload logged data from a 2625A. The response is a single ASCII string, which encodes the raw binary data stored at the specified <index> position. The logged data is also retained in the 2625A.

The measurement data returned from the 2625A is in the (binary) IEEE single-precision floating point format. Making use of this data can be difficult and is very machine dependent. A working example, using the C programming language on an IBM PC, is provided in this appendix. This example uses a pre-computed LOG_BIN?response string, and checks that the conversion process works as expected.

Two steps are required in adapting the LOG_BIN? response string for use with your computer.

∙First, you must decode the ASCII string into binary data. For example, one possible LOG_BIN? response string is:

LOG_BIN? 1 42@Y40BA00oo000007o0001oP000?h000 =>

This ASCII string represents the following binary (hex) data:

10 24 29 10 04 91 00 0f ff

00 00 00 00 7f c0 00 00 7f

80 00 00 3f 80 00 00 00 00

∙Second, you must convert this binary data into valid floating point numbers for your underlying computer architecture.

Decoding the ASCII String

The ASCII response string contains six bits of raw data for each ASCII character, offset from ASCII ’0’ (0x30 hex, 48 decimal). Therefore, the conversion process subtracts 48 from the integer value of each character, then shifts it into place. Each set of four ASCII characters form three bytes of raw data. The number of bytes of raw data depends on the number of channels for the scan. The following C code converts a LOG_BIN? response string into a byte array:

E-1

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Fluke 2620A user manual Binary Upload of Logged Data LOGBIN? 2625A only, Decoding the Ascii String
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2625A, 2620A specifications

The Fluke 2625A is a sophisticated data logger designed for a wide range of industrial and laboratory applications. This versatile instrument excels in capturing and monitoring temperature and voltage measurements with precision and reliability. One of its standout features is its ability to record data from various sensors, making it ideal for environments where comprehensive data acquisition is critical.

Equipped with a large LCD display, the Fluke 2625A provides clear and user-friendly access to real-time measurement data. Its graphical interface allows users to visualize trends and monitor readings easily, which significantly enhances usability. The device supports a variety of input types and can connect to thermocouples, RTDs, and other sensors, offering great flexibility for various measurement tasks.

The Fluke 2625A employs advanced measurement technologies that ensure accuracy in data logging. With a high sampling rate, it captures fast-changing signals while maintaining data integrity. The device features a built-in memory that allows for extensive logging, accommodating long-term monitoring tasks without requiring constant oversight. Users can set it to log data at specified intervals, offering customizable solutions for different monitoring needs.

Another significant characteristic of the Fluke 2625A is its robust communication capabilities. The device supports USB and RS-232 interfaces for easy connectivity with computers and other devices, making data transfer and analysis seamless. This feature is especially beneficial for users who need to compile or analyze large sets of data quickly.

Furthermore, the Fluke 2625A is designed with durability in mind. Its rugged construction makes it suitable for challenging environments, including those with high levels of vibration, dust, or moisture. This reliability ensures that the device can withstand the rigors of fieldwork while still delivering accurate measurements.

In summary, the Fluke 2625A is a powerful data logger that combines versatility, accuracy, and reliability. Its user-friendly interface, advanced measurement technologies, and robust design make it an essential tool for professionals in various industries, from manufacturing and HVAC to research and development. Whether monitoring temperature changes in a laboratory or assessing voltage levels in an industrial setting, the Fluke 2625A stands out as a trusted solution for effective data logging and analysis.
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