Binary Upload of Logged Data

Appendix C

Introduction

The LOG_BIN? <index> query can be used to quickly upload logged data from a 2635A. 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 2635A.

The measurement data returned from the 2635A 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

C-1

2635A specifications

The Fluke 2635A is a highly advanced multichannel data acquisition system designed for engineers and technicians requiring precision and versatility in their measurement tasks. This instrument excels in monitoring and capturing data from various sources, making it a valuable tool in laboratories, production environments, and field applications.

One of the standout features of the Fluke 2635A is its ability to support up to 20 measurement channels. Users can simultaneously monitor multiple signals, which is crucial for complex testing scenarios where numerous variables need to be tracked. The device is equipped with a 6.5-digit precision measurement capability that ensures high accuracy and resolution in readings. This level of precision is particularly beneficial in applications such as environmental monitoring, research and development, and industrial process control.

The unit incorporates a variety of measurement modes, including voltage, current, temperature, and resistance, making it exceptionally versatile. The Fluke 2635A not only handles standard signals but also integrates with various transducers, providing extensive compatibility for users engaged in diverse testing applications.

To enhance data management, the Fluke 2635A offers advanced data logging capabilities. Data can be stored internally or transferred to external devices for further analysis. The internal memory can accommodate extensive datasets, which can be crucial in long-term monitoring tasks. Integration with external software enables users to analyze and visualize data effectively, allowing for informed decision-making based on comprehensive results.

The user interface is designed for ease of use, featuring a large, bright LCD display that clearly presents measurements and status information. The device is also equipped with a simple navigation system, allowing users to switch between channels and measurement types without hassle.

In terms of construction, the Fluke 2635A is built to withstand rigorous environments. It features a robust design that ensures reliability and durability, making it suitable for both laboratory settings and field operations. Furthermore, the device supports a wide temperature range, thus enabling usage in diverse conditions.

Overall, the Fluke 2635A is a powerful and flexible instrument that provides precise measurements across multiple channels, supporting a wide range of applications. Its advanced technology, combined with user-friendly features, makes it an essential tool for professionals in various fields. The combination of accuracy, flexibility, and durability solidifies its standing as a trusted choice for data acquisition and monitoring tasks.

Fluke 2635A user manual Binary Upload of Logged Data, Decoding the Ascii String

Models: 2635A