EnDat

Table of Contents

• Introduction
• Features Supported
• Features Not Supported
  • Limitations
• SysConfig Features
• ENDAT Design
• Example
• API

Introduction

EnDat is a bidirectional interface for position encoders. During EnDat operation the EnDat receiver receives position information from the EnDat position encoder.

Features Supported

• EnDat 2.2 command set
• EnDat 2.1 command set
• Interrupted and continuous clock mode
• Cable length up to 100m @8MHz
• Propagation delay compensation (capable of handling different propagation delay of different propagation delay of different channels in concurrent multi channel configuration)
• Automatic estimation of propagation delay
• Receive on-the-fly CRC verification of position, parameters and additional information
• Two modes of operation - host trigger and periodic trigger
• Channel select
• Concurrent multi channel support (up-to 3 encoders with identical part number @ 8MHz maximum)
• "Multi Channel with Encoders of Different Make" using load share mode (Each of PRU, RTU-PRU, and TX-PRU from one PRU-ICSSG slice handles one channel)
• Safety Readiness: Recovery time
• Clock up to 16MHz with single channel and load share mode (multi channel)

Features Not Supported

In general, peripherals or features not mentioned as part of "Features Supported" section are not supported in this release, including the below

• Independent clocks on multi channel mode.
• Continuous clock mode in Multi-channel single PRU mode

Limitations

This section describes known limitations of the current implementation in multi-channel single PRU mode.

• Clock above 8 MHz: it is not possible to over sample, downsample and store one bit for all three channels in one clock cycle time.
• Reset command CRC failure: The encoder which takes more time in reset operation will show CRC failure because the reset time is not the same for each encoder so the acknowledgment will not arrive on same time for all encoders at the master end.
  

SysConfig Features

Note

It is strongly recommend to use SysConfig where it is available instead of using direct SW API calls. This will help simplify the SW application and also catch common mistakes early in the development cycle.

SysConfig can be used to configure things mentioned below:

• Selecting the ICSSG instance. (Tested on ICSSG0)
• Selecting the ICSSG PRU slice.(Tested on ICSSG0-PRU1)
• Configuring PINMUX.
• Channel selection.
• Selecting Multi Channel with Encoders of Different Make" using load share mode.

ENDAT Design

EnDat Protocol Design explains the design in detail.

Example

EnDAT Diagnostic

API

APIs for ENDAT Encoder