IS200TVIBH2BCC处理器模块,模块控制器
模拟输入框图模拟输入是差分的；也就是说，转换后的数据是电压IN+和IN-之间的差值，如图3-2所示。差分输入配置对噪声和接地电流的敏感性要低得多。两个输入都参考一个电压，称为COM。IN端子相对于COM的平均电压称为模式电压。不同的信号源y具有不同的模式电压，如V（CM1）和V（CM2）所示。该模式电压可能由接地位置的差异或输入信号本身的真实性引起。为了参考浮动源和限制模式电压，COM端子应连接到源本身的输入的任一侧。在没有特殊设计考虑的情况下，参考COM端子的线路上的模式电压、差分输入电压和ise的总和限制为±11伏，或模块的最终结果。输入模块提供一些滤波以防止高频尖峰，但超过此值的低频信号将产生错误转换。a4738 IN VDIF1 VCM1 IN COM IN VDIF1 VCS2 IN COM图9-3。Alog输入模式电压9 9-6 Series 90–30 PLC I/O模块规格–2000 GFK–0898F%AQ数据表是Series 90-30中存储信息的存储位置。电流和电压模拟模块均可用于Series 90-30 PLC；然而，Series 90-30无法识别两种类型的模拟之间的差异。用户必须按照Series 90-30可编程控制器安装手册GFK-0356和Logicster 90 Series 90-30/20/Micro编程软件用户手册GFK-0466中的说明配置Series 90-30 PLC系统。配置后，两个alog将对应于数据表中的32位。a4739 D/A转换器串并转换器90-30系列数据表%AQ用户连接沿模块过滤器图9-4。Alog模块的Alog框图接口Series 90-30 PLC使用%AQ和%AI数据表中的数据驱动或记录如图3-1和3-3所示的数值。alog数据在2的补码堡垒中处理。为了转换的目的，二的补码由一个正数的biry码（由最高有效位中的0（零）表示）和每个正数的2的补码组成，以表示其负数。要将负数从2的补码转换为biry，请反转每一位并加一。下面的操作是16位字的示例转换。2的补码鸟在数据表中以十分位数而不是六分位数工作，当您使用alog数据时，可以更容易地进行计算。您可以将%AQ和%AI数据表中的数据用于任何th或数据函数，而不必进行任何转换或2的补码。在任何th计算中使用原始数据时，通常使用双精度th。通用阿洛格模块信息部分9 GFK–0898F第9章–通用阿洛克模块信息部分9-7您可以使用以下公式和表3-3中的值来查找用于编程的相应数据字和模拟值。数据表中的数据位由于alog模块中使用的转换器是13位转换器，因此数据表中所有16位都包含转换所需的数据。12位的版本被放置在对应于模拟点的16位数据字内（在%AQ或%AI表中）。Series 90-30系统以不同的方式处理各种模拟模块的集成。Series 90-30系统忽略%AQ表中额外位中的数据，并使用这些位与模块通信。在将数据发送到模块之前，还将%AQ数据字中的数据从2的补码转换为符号数量。在将数据放入%AI数据表中的单词之前，不会处理来自输入模块的数据。
Alog Input Block Diagram The alog inputs are differential; that is, the converted data is the difference between the voltages IN+ and IN– as shown in Figure 3-2. The differential input configuration is much less sensitive to ise and ground currents. Both inputs are referenced to a voltage, referred to as COM. The average voltage of the IN termils with respect to COM is referred to as Mode Voltage. Different sigl sources y have different mode voltages, shown as V (CM1) and V (CM2). This mode voltage y be caused by differences in location of grounds, or by the ture of the input sigl itself. To reference floating sources and limit mode voltages, the COM termil should be connected to either side of the input at the source itself. Without special design considerations, the sumtion of the mode voltage, the differential input voltage and ise on the lines referenced to the COM termils is limited to ±11 volts, or dage y result to the module. The input modules provide some filtering to protect against high frequency spikes, but low frequency sigls exceeding this will produce erroneous conversions. a44738 IN VDIF1 VCM1 IN COM IN VDIF1 VCM2 IN COM Figure 9-3. Alog Input Mode Voltage 9 9-6 Series 90–30 PLC I/O Module Specifications – 2000 GFK–0898F s The %AQ data table is a memory location within the Series 90-30 where the infortion is stored. Both current and voltage alog modules are ailable for the Series 90-30 PLC; however, the Series 90-30 does t recognize the difference between the two types of alog s. The user must configure the Series 90-30 PLC system as described in the Series 90-30 Programble Controller Installation nual, GFK-0356 and the Logicster 90 Series 90-30/20/Micro Programming Software User’s nual, GFK-0466. After configuration, the two alog s will correspond to 32 bits in the data table. a44739 D/A CONVERTER SERIAL TO PARALLEL CONVERTER SERIES 90-30 DATA TABLE % AQ USER CONNECTIONS ALOG MODULE FILTER Figure 9-4. Alog Block Diagram Interface to Alog Modules The Series 90-30 PLC uses the data within the %AQ and %AI data tables to drive or record alog lues as shown in Figures 3-1 and 3-3. The alog data is handled in a 2’s complement fort. Two’s complement, for conversion purposes, consists of a biry code for positive gnitudes (represented by a 0 (zero) in the most significant bit), and the 2’s complement of each positive number to represent its negative. To convert negative numbers from 2’s complement to biry, invert each bit and add one. The operation below is an example conversion of a 16-bit word. 2’s Complement Biry Working in decil fort, instead of hexadecil, within the data tables will allow easier calculations when you are working with alog data. You can use the data in the %AQ and %AI data tables for any th or data function without having to do any conversion or 2’s complement th. When using raw data in any th calculations, you would usually use double precision th. General Alog Module Infortion 9 GFK–0898F Chapter 9 – General Alog Module Infortion 9-7 You can find corresponding data words and alog lues for programming purposes by using the following equations and the lues in Table 3-3. Data Bits within the Data Tables Since converters used in the alog modules are 13-bit converters, t all of the 16 bits in the data tables contain data required for the conversion. A version of the 12 bits is placed within the 16-bit data word corresponding to the alog point (in %AQ or %AI tables). The Series 90-30 system handles the integration differently for the rious alog modules. The Series 90-30 system disregards the data placed in the extra bits in the %AQ table and uses those bits for communications with the module. The also converts the data in the %AQ data word from 2’s complement to sign gnitude fort before sending the data to the module. The does t nipulate the data from the input modules before placing it within the word in the %AI data table.
