Omega Engineering EN-EIC-325-PCI manual Introduction, Encoder Counters

APPENDIX A: SPECIFICATION

Introduction

A half-size PC card.

Supports four optical encoders with either Square-wave or Sine output, both linear and rotary types.

Directly connected to the encoders and also provides the excitation.

Single / Multiple encoder pulses: Interpolation = 1, 2 or 4 (software selectable). Independent operation mode for each axis.

General inputs, an index input per each encoder, and an input to request a snapshot of all counters in real-time.

The user may instruct the card to generate an "Event Signal" output upon reaching a pre-defined set-point, counter overflow, or index (marker) signal.

General outputs, an "Event Signal" output per each encoder, and a "Voltage Failure" indicator.

All outputs are opto-isolated. Max. input pulse rate: 500 kpps. Software included:

Drivers for Win95/98/NT/2K/XP and how to communicate under DOS.

Useful utility that allows immediate read/test of the encoders. Detailed example in VB and basic example in Visual C.

Encoder Counters

24 bit up/down latch counter for each axis. Counter's range is from 0 to 16777215. In case the user needs also negative values, he may consider the range 0 – 16777215 as -8388608 – +8388607.

Each counter has a corresponding programmable set-point value.

The user may instruct the card to generate an "Event Signal" output when card's counter reaches its corresponding set-point value, or at counter overflow.

User may request a snapshot of a counter without stopping the counting process, thus not losing data. The operation may be accomplished either by software or, in real-time, by a hardware input.

A counter may be reset by encoder's index output and/or by request via user's software.

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