1756-IF8A 模拟输入模块

1756-IF8A 模拟输入模块

Allen-Bradley 1756-IF8是ControlLogix可编程自动化控制器(PAC)系列的模拟输入模块。该模拟输入模块具有八(8)个输入通道，可针对各种输入信号进行配置，例如+/-10VDC、0-10VDC和0-5VDC电压信号以及0-20 mA电流信号。该模块通常用于连接模拟信号发生仪器和设备，如发射器、传感器、信号分离器、信号隔离器、面板仪表和其他类似设备。

1756-IF8是具有高转换分辨率的单槽模块。它的分辨率从15位到16位不等。具体模块分辨率为10.25V:对于+/-10VDC，320V/计数(15位加号双极性)，160V/计数(16位)；对于0-10VDC，80 /V计数(16位)；对于0-5VDC和0…20.5mA:对于0-20 mA信号，每个计数(16位)为0.32 A。

该模块的安装实例数量实际上没有限制。大多数ControlLogix控制器能够处理多达4000个模拟I/O信号。1756-IF8可以沿着控制器安装在本地机箱中，也可以安装在分布式I/O机架中。

1756-IF8使用适马-德尔塔转换方法，并将接收信号保存在整数模式(左对齐，2 s补码)IEEE 32位浮点寄存器中。它使用1756-TBCH和1756-TBSH可移动接线板(RTB ),带有用户定义的机械键控。

模块扫描时间也因接线配置而异。对于单线接线，扫描时间为16-488毫秒，对于4点差分，扫描时间为8-244毫秒，而对于2点差分输入，扫描时间为5-122毫秒。

1756-IF8有三种不同的接线方式:单端接线、差分接线和高速模式差分接线。在单端布线中，所有输入设备都连接到一个公共地，它允许将信号输入的一侧与信号地进行比较。然后，模块使用该差值为控制器生成数字数据。使用单端接线方法可以zui大限度地增加模块的可用通道数量。当您的应用可能有单独的信号对或没有公共接地时，以及当您需要提高环境中的抗扰度时，您应该使用差分布线。这种布线方法中的通道并不是完全相互隔离的。但是，当您需要尽可能zui快的数据更新时，您应该使用高速模式差分布线方法。请注意，该模式仅允许使用模块上每四个通道中的一个。1756-IF8的具体功能包括模块滤波器、欠量程/超量程检测、过程报警、断线检测、多输入范围、实时采样、数字滤波器和速率报警。其底板电压和电流额定值为5.1伏DC、zui大150毫安、24伏DC和zui大40毫安。它的输入电流范围为4至20毫安，输入电压范围为-10至10伏。功耗为1.73瓦，zui大过压保护为30伏DC(电压)和8伏DC(电流)。

1756-IF8A 模拟输入模块

Allen-Bradley 1756-IF8 is an analog input module for the ControlLogix Programmable Automation Controller (PAC) family. The analog input module has eight (8) input channels that can be configured for a variety of input signals, such as +/-10VDC, 0-10VDC, and 0-5VDC voltage signals, and 0-20 mA current signals. The module is commonly used to connect analog signal generating instruments and devices such as transmitters, sensors, signal separators, signal isolators, panel meters, and other similar devices.

The 1756-IF8 is a single slot module with high conversion resolution. Its resolution ranges from 15 to 16 bits. The specific module resolution is 10.25V: for +/-10VDC, 320V/ count (15-bit plus sign bipolar), 160V/ count (16-bit); For 0-10VDC, 80 /V count (16 bits); For 0-5VDC and 0... 20.5mA: For 0-20 mA signals, each count (16 bits) is 0.32 A.

There is virtually no limit to the number of installed instances of this module. Most ControlLogix controllers are capable of handling up to 4,000 analog I/O signals. The 1756-IF8 can be mounted in a local chassis along the controller or in a distributed I/O rack.

The 1756-IF8 uses the Sigma Delta conversion method and saves the received signal in an integer mode (left justified, 2 s complement)IEEE 32-bit floating-point register. It uses the 1756-TBCH and 1756-TBSH removable patch boards (RTB) with user-defined mechanical keying.

Module scan times also vary depending on the wiring configuration. The scan time is 16-488 ms for a single wire connection, 8-244 ms for a 4-point differential, and 5-122 ms for a 2-point differential input.

The 1756-IF8 has three different wiring modes: single-ended, differential, and high-speed differential. In single-ended wiring, all input devices are connected to a common place, which allows the side of the signal input to be compared with the signal ground. The module then uses this difference to generate digital data for the controller. Using the single-ended wiring method maximizes the number of available channels for the module. You should use differential wiring when your application may have separate signal pairs or no common ground, and when you need to improve immunity in your environment. The channels in this wiring method are not completely isolated from each other. However, when you need the fastest data update possible, you should use the high-speed mode differential wiring method. Note that this mode allows only one of every four channels on the module to be used. Specific features of the 1756-IF8 include modular filters, underrange/overrange detection, process alarm, line break detection, multiple input ranges, real-time sampling, digital filters, and rate alarms. Its baseboard voltage and current ratings are 5.1 V DC, up to 150 mA, 24 V DC, and up to 40 mA. It has an input current range of 4 to 20 mA and an input voltage range of -10 to 10 volts. The power consumption is 1.73 watts and the maximum overvoltage protection is 30 volts DC(voltage) and 8 volts DC(current).

1756-IF8A 模拟输入模块