3B系列概述

简介

3B Series3B系列信号调理I/O子系统提供了一种低成本、灵活的方法,把模拟传感器信号传送至数据采集、监控或控制系统,且没有内在的噪声、非线性、漂移、额外电压等问题。 根据设计,系列模块可以直接接受来自热电偶、RTD、交流和直流应变计、扭矩传感器、频率传感器和LVDT的模拟信号,以及毫伏或过程电流信号。 这些模块可以把传感器输出信号放大、隔离、线性化并转换至标准化模拟输入端,供高电平模拟I/0子系统使用。 3B系列子系统由19"继电器架、通用安装背板和一系列插入式(每个机架最多16个)输入输出信号调理模块组成。

同时提供8通道和4通道背板。 每个背板都包括用于连接传感器输入和电流输出的螺纹连接端子,以及用于将高电平单端电压输出连接到用户设备的26引脚连接器。

输入模块具有针对特定传感器或模拟信号而优化的完整信号调理电路,并且提供两个同步高电平模拟输出: 0至+10 V(或±10 V)和4-20 mA(或0-20 mA)。

an0026_silo输入模块具有针对特定传感器或模拟信号而优化的完整信号调理电路,并且提供两个同步高电平模拟输出: 0至+10 V(或±10 V)和4-20 mA(或0-20 mA)。

ADI 3B系列信号调理子系统旨在轻松解决测量和控制应用中的信号调理问题。 典型用途包括基于微型计算机的数据采集系统、可编程控制器、模拟记录器、专用控制系统以及需要监控温度、压力、流量和模拟信号的任何其他应用。 由于每个输入模块都有两个同步输出,因此,可以利用电压输出为基于微处理器的数据采集或控制系统提供输入,同时还可将电流输出提供给模拟传输、操作员界面或模拟备份系统使用。


Features and Benefits

  • 面向各种传感器、热电偶、RTD、频率传感器和LVDT、毫伏级、伏特级和毫安级输入的隔离式输入信号调理器
  • 面向交流和直流应变计、扭矩传感器和称重传感器的非隔离式输入信号调理器
  • 隔离式电流输出模块,4-20 mA/0-20 mA
  • 同步电压和电流输出
  • 提供0至+10 V或±10 V、4-20 mA/0-20 mA输出
  • 基于变压器的可靠隔离
  • -25°C至+85°C工作温度范围的额定规格
  • 所有型号的模块精度均为±0.1%
  • 斩波稳定放大功能确保低漂移(±1 µV/°C)和出色的长期稳定性
  • 用户可通过AC1310范围调整卡进行配置

设计特性和用户优势

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易于使用

通过螺纹端子直接连接传感器、标准化的高电平输出、每个单元均经工厂预校准、模块化设计,这些特点使3B系列子系统使用起来极其方便。 子系统采用面向工业环境的耐用型封装,易于安装和维护。

高可靠性

为了确保高可靠性,所有现场接线端子均提供130 V或220 V rms常模保护。 镀金引脚和插槽连接器用于整个系统,确保连接可靠性。 隔离式模块提供针对高共模电压的保护,其设计符合IEEE瞬态电压保护标准(ANSI/IEEE C37.90.1-1989)。

高性能

高质量信号调理系列具有±0.1%的校准精度和斩波放大功能,确保低漂移(±1 µV/°C)和出色的长期稳定性。 对于热电偶应用,每个通道的背板中都提供了高精度冷结检测机制。 为RTD、应变计和LVDT型号提供了低漂移传感器激励。 RTD型号和3B47热电偶型号会线性化输入信号以提供与温度呈线性关系的输出。

高噪声抑制能力

根据设计,3B系列子系统具有出色的共模和串模噪声抑制及抗RFI/EMI性能,可以在恶劣电气环境中精确处理低电平信号。

 3B Series Functional Block Diagram
 
图1. 3B系列系统功能框图


3B系列输入模块

Figure 2 shows a functional diagram for the Model 3B37 isolated thermocouple signal conditioner. The input signal is filtered, amplified and has cold junction compensation applied before the isolation barrier. The outputs of the module are isolated from the input (up to ±1500 V peak) and factory calibrated for 0 to +10V (voltage output) and 4-20 mA (current output), which correspond to the specified input span.

The input modules are available in several factory-calibrated input ranges. Each input module includes separate screwdriver-adjustable zero and span potentiometers for both of the outputs which can be used for fine calibration within the chosen range. The voltage and current adjustments are independent and non-interactive, enabling precise calibration of both outputs.

The current output of each input module has two user-programmable jumper options. One option enables the user to program the current output to be proportional to either a 0 to +10 V or a -10 V to +10 V voltage output. The second option enables the user to set the current output span to 4-20 mA or 0-20 mA. All modules are shipped from the factory configured so that the current output is proportional to the 0-10 V output range and all current outputs are 4-20 mA.

Model 3B37 Functional Block Diagram
 
 Figure 2. Model 3B37 Functional Block Diagram

Input Module Features

  • Wide Variety of Sensor Inputs:
    Thermocouples
    RTD's
    ac and dc Strain Gauges
    Torque Transducers
    Frequency Transducers
    LVDTs
  • Dual High Level Outputs
    Voltage: 0 to +10 V or ±10 V
    Current: 4-20 mA/0-20 mA
  • Mix and Match Module Capability
  • High Accuracy: ±0.1%
  • Low Drift: ±1µV/°C
  • Reliable Transformer Isolation:
    ±1500 V Peak and CMR = 160 dB
  • Meets ANSI/IEEE Transient Protection
  • Input Protection: 130 V or 220 V rms Continuous








Each input module is a single-channel signal conditioner which plugs into a socket on the backplane and accepts its signal from the input screw terminals. All input modules provide input protection, amplification and filtering of the input signal, accuracy of ±0.1%, low drift of ±1 µV/°C (low-level input modules), and feature two high-level analog outputs that are compatible with most process instrumentation. The isolated input modules also provide ±1500 V peak isolation.

The choice of a specific 3B module depends upon the type of input signal. Input modules are available to accept millivolt, volt, process current, thermocouple, RTD, ac and dc strain gage, frequency and LVDT inputs. The voltage output of each module is available from the system I/O connector while the current output is available on the output screw terminals.

Wide Zero Suppression Capability

an0036A wide zero-suppression capability and easy-custom ranging are available with a unique plug-on ranging card (AC1310). If a special input range is desired, it can be provided by ordering the externally-programmable version of the desired module (i.e. 3B32-00) and the plug-on ranging card, AC1310.This card houses user-supplied resistors which determine the zero and span of the desired range. RTD modules accept an additional resistor to establish linearization of the input signal, while the 3B37 thermocouple module uses an additional resistor to set the cold junction compensation level. This ranging capability enables the user to provide zero suppression of up to and beyond 100% of the input range and provides a very wide range of span modification. This enables the user to map any portion of the input signal to the full output span. For example, a user who wants to measure temperature with a thermocouple in the range of +800°C to +900°C can use this ranging card for greater system resolution within that defined 100°C temperature span. This tremendous flexibility should satisfy virtually any requirement. The resistor values are determined by equations defined for each module. A software program (3B-CUSTOM) is also available to assist in quickly calculating the resistor values, using only the user-defined input and output requirements.

Special ranges can also be factory configured. Analog Devices will provide this service when a model 3BXX-CUSTOM is ordered with the desired range. (The 3B47 linearized thermocouple input module can not be user ranged with an AC1310 since approximately 15 components are required for linearization. A factory configured 3B47-CUSTOM can provide the desired input range.)


3B系列输出模块

The 3B39 output module accepts a high-level analog signal from the system connector and provides a current output on the output screw terminals. When a +24 V loop supply is used, loads up to 850 Ω can be driven. If desired, +15 V can be used to power the output modules with a smaller load (up to 400 Ω). Each output module features high accuracy of ±0.1%.The 3B39 provides ±1500 V peak common mode voltage isolation protection.

The transfer function provided by each output module is:
  • Input - 0 to +10 V or ±10 V
  • Output - 4 to 20 mA or 0 to 20 mA (Jumper Selectable)

Figure 3 shows a functional diagram of Model 3B39. The input signal drives a voltage to current converter through the isolation barrier. Each output module has zero and span potentiometers for fine calibration of the isolated current output. The output module has two user-programmable jumper options. One option enables the user to program the current output to be proportional to either a 0 to + 10 V input or a - 10 V to +10 V input. The second option enables the user to set the current output span to 4-20 mA or 0-20 mA. All output modules are shipped from the factory with the current output set proportional to the 0 to +10 V input and all current outputs are 4-20 mA.


 Model 3B39 Functional Block Diagram
 
Figure 3. Model 3B39 Functional Block Diagram


Features and Benefits

  • High-Level Voltage Inputs
  • Isolated Process Current Output
  • High Accuracy : ±0.1%
  • Reliable Transformer Isolation: ±1500 V Peak Continuous
  • Meets ANSI/IEEE Transient Protection
  • Output Protection : 130 V rms Continuous
  • Reliable Pin and Socket Connections
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