# P.I. Engineering SDK Help

# Data Report Description Overview

## Overview

The following sections describe the data available from the P.I. Engineering products. The PID (Product Identification number) , Hid Usage and Usage Page are obtained using the EnumeratePIE() call. The Input Report contains information that can be obtained by using the ReadData() or ReadLast() calls or the SetDataCallback() feature. The Output report contains information on writing to the device using the WriteData() call. The bytes are numbered as they are seen when calling the ReadData() or ReadLast() and how they would be filled for the WriteData(). The first byte of the report is reserved for the Report ID (note some non PC operating systems may omit the Report ID). Information is passed between the computer and the device via bytes of data. A byte consists of 8 bits which have a value of either 0 or 1. The Reports describe exactly what information is stored in each byte. Figure 1 shows the break down of 1 byte (8 bits) into its corresponding bits for reference. In the example shown 00010001 is converted into a decimal value of 17.

Figure 1: Breakdown of 1 byte.

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