Designed, Built, Tested
Board pictured here has been fully assembled and tested.

Overview

設計リソース

設計サポートファイル

  • Schematic
  • Bill of Materials
  • PCB layout
  • Nexys 3 platform
  • Zedboard platform

設計ファイルのダウンロード 47.02 M

評価用ボード

型番に"Z"が付いているものは、RoHS対応製品です。 本回路の評価には以下の評価用ボードが必要です。

  • MAXREFDES12# ($70.17) EV Kit
在庫確認と購入

説明

産業用制御、産業用オートメーション、モータ制御、プロセス・オートメーションの各アプリケーションでは、バイナリ/デジタルのセンサーやスイッチが高い頻度で必要になります。多くの場合、システムでは各センサーのチャンネルを絶縁するために多数のオプト・カプラが必要です。Corona(MAXREFDES12)サブシステム・リファレンス設計では、プログラマブル・ロジック・コントローラ(PLC)デジタル入力モジュールのフロントエンド・インターフェース回路が提供されます。シリアライゼーション機能により、絶縁に使用されるオプト・カプラの数を大幅に削減できます。このリファレンス設計は高電圧入力(最大36V)に対応しており、絶縁型電源と絶縁型データを特長としています。また、すべてを統合することで小型化を実現しています。Coronaの設計では、オクタル(8回路)デジタル入力変換器/シリアライザ(MAX31911)、データ絶縁デバイス(MAX14850)、絶縁型電源用 Hブリッジ・ トランス ・ドライバ(MAX13256)が統合されています。Coronaデジタル入力回路ソリューションは、主にPLC、産業用オートメーション、プロセス・オートメーション、モータ制御の各アプリケーションのデジタル入力モジュール向けに設計されています。

機能と利点

特長

  • 8つの高電圧入力チャンネル(最大36V)
  • SPI インターフェースによるオン・チップ8対1シリアライゼーション
  • 5V内蔵レギュレータ
  • 絶縁型の電源とデータ
  • 小面積のプリント回路基板(PCB
  • デバイス・ドライバ
  • C言語のサンプル・ソース ・コード
  • Pmod™互換のフォーム・ファクタ

アプリケーション

  • ビルディング・オートメーション
  • PLC用デジタル入力モジュール
  • 産業用オートメーション
  • モータ制御
  • プロセス・オートメーション

Details Section

Required equipment:

  • Windows® PC with one USB port
  • Corona (MAXREFDES12#) board
  • Corona-supported platform (i.e., Nexys 3 development kit or ZedBoard kit)
  • One 24V 1A DC power supply
  • Download, read, and carefully follow each step in the appropriate Corona Quick Start Guide:

Corona (MAXREFDES12) Nexys 3 Quick Start Guide

Corona (MAXREFDES12) ZedBoard Quick Start Guide

Figure 01b

The Pmod specification allows for both 3.3V and 5V modules as well as various pin assignments. This module works with either 3.3V or 5V supply voltages and uses the SPI pin assignments as illustrated.

The power requirements are shown in Table 1. The currently supported platforms and ports are shown in Table 2.

Table 1. Power Requirements for the Corona Subsystem Reference Design
Power Type Jumper Shunt Power Name Input Voltage (V) Input Current (mA, typ)
Isolated power JU1: 1–2 U3 VCAA 3.3 19.4
5 27.2
U1 VCC24V 12 13.6
24 14.5
Field power JU1: 2-3 U3 VCAA 3.3 19.4
5 27.2
U1 VCC24V 12 8.2
24 8.2
 Table 2. Supported Platforms and Ports
Supported Platforms Ports
Nexys™ 3 platform (Spartan®-6) JA1
ZedBoard™ platform (Zynq®-7020) JA1

The Corona subsystem is an isolated, octal, digital input translator/serializer. The design includes an octal, digital input translator/serializer (MAX31911), an H-bridge transformer driver (MAX13256), and a six-channel digital isolator (MAX14850).

The MAX31911 (U1) industrial interface serializer translates, conditions, and serializes the 24V digital output of sensors and switches used in industrial, process, and building automation to CMOS-compatible signals required by microcontrollers. It provides the front-end interface circuit of a PLC digital input module. The device features integrated current limiting, lowpass filtering, and channel serialization. Input current limiting allows a significant reduction in power consumed from the field voltage supply as compared to traditional discrete resistor-divider implementations. Selectable on-chip lowpass filters allow flexible debouncing and filtering of sensor outputs based on the application. On-chip serialization allows a large reduction in the number of optocouplers used for isolation. For enhanced robustness with respect to high-frequency noise and fast electrical transients, a multibit CRC code is generated and transmitted through the SPI port for each 8 bits of data. The on-chip 5V voltage regulator can be used to power external optocouplers, digital isolators, or other external 5V circuitry.

The MAX13256 (U2) provides an isolated, functional insulation class power solution that accepts an 7.6V to 36V DC supply, and converts it to an isolated 7V to 36V DC supply with an off-the-shelf TGMR-501V6LF Halo® transformer with a 1:1 primary to secondary turns ratio plus an external on-board full bridge rectifier.

The MAX14850 (U3) accomplishes data isolation. On the Pmod side, the voltage supply can be 3.3V or 5V. (The Pmod power output for both the Nexys 3 and ZedBoard platforms is fixed at 3.3V.) On the MAX31911 side, the voltage supply is 5V. The combined power and data isolation achieved is 600VRMS.

To use the on-board isolation circuits, move the shunt on jumper JU1 to the 1–2 position and apply 7.6V to 36V DC supply on terminals TP3 and TP4. If the on-board isolation circuit is not required, move the shunt on jumper JU1 to the 2-3 position and apply 7V to 36V DC supply on terminals TP1 and TP2. See Table 1 for the jumper settings and the input current requirements.

Detailed Description of Firmware for Nexys 3 Platform

The Corona firmware design was developed and tested for the Nexys 3 development kit. The design targets a MicroBlaze™ soft core microcontroller placed inside a Xilinx® Spartan-6 FPGA.

The firmware is a working example of how to initiate the system and continuously read and display the MAX31911 register values. The simple process flow is shown in Figure 2. The firmware is written in C using the Xilinx SDK tool, which is based on the Eclipse™ open source standard. Custom Corona-specific design functions were created utilizing the standard Xilinx XSpi core version 3.03a. The SPI clock frequency is set to 3.125MHz.

Figure 2. The Corona firmware flowchart for Nexys 3 platform.

Figure 2. The Corona firmware flowchart for Nexys 3 platform.

The complete source code is provided to speed up customer development. Code documentation can be found with the corresponding firmware platform files.

Detailed Description of Firmware for ZedBoard Platform

Figure 3. The Corona firmware flowchart for ZedBoard platform

Figure 3. The Corona firmware flowchart for ZedBoard platform

The complete source code is provided to speed up customer development. Code documentation can be found with the corresponding firmware platform files.

The following picture illustrates a test case for system operation on the ZedBoard platform. A 24V DC supply is applied on the TP3 and TP4 input power connectors. 24V is applied on channel 2 and channel 8 of the digital inputs. All other digital inputs are grounded. The OLED shows the register value as 0x8218. The LD7 (corresponding to input channel 8) and LD1 (corresponding to input channel 2) LEDs are lit up.

Figure 4. The Corona subsystem lab operation on the ZedBoard platform.

Figure 4. The Corona subsystem lab operation on the ZedBoard platform.

  • ARM is a registered trademark and registered service mark of ARM Limited.
  • Cortex is a registered trademark of ARM Limited.
  • Eclipse is a trademark of Eclipse Foundation, Inc.
  • Halo is a registered trademark of Halo Electronics, Inc.
  • MicroBlaze is a trademark of Xilinx, Inc.
  • Nexys is a trademark of Digilent Inc.
  • Pmod is a trademark of Digilent Inc.
  • Spartan is a registered trademark of Xilinx, Inc.
  • Windows is a registered trademark and registered service mark of Microsoft Corporation.
  • Xilinx is a registered trademark and registered service mark of Xilinx, Inc.
  • ZedBoard is a trademark of ZedBoard.org.
  • Zynq is a registered trademark of Xilinx, Inc.

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