Data Acquisition (DAQ) and Control from Microstar Laboratories

Knowledge Base: Processing

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Q10078 Conversion between Integer and Voltage Values

Tags: Help, Integer to voltage, Conversion

Applies to: xDAP, DAP, iDSC

How do I interpret the integer values for the acquired data reported by a DAP or an iDSC?

The units used on an xDAP, a DAP, or an iDSC to represent voltage are 16-bit integers. Use formula A below to convert from integer to voltage, where FS means full scale. For this article, the full scale is interpreted as the the maximum voltage (above zero) of the input channel given the input voltage range in hardware and the gain specified in software. For example, FS is 5 for a voltage range of +/-5V and a unity gain. For a PCI DAP board, refer the hardware manual for the model for information on selecting the input voltage range in hardware.

A. Voltage = Integer * FS / 32768

Use formula B below to convert from voltage to integer:

B. Integer = Voltage * 32768 / FS

Examples:

  1. At a gain of 10 for an input range of +/-10V in hardware, the maximum voltage range is then +/-1V. The value of FS is 1.
  2. At a gain of 100 for an input range of +/-5V in hardware, the maximum voltage range is then +/-0.05V. The value of FS is 0.05.