HIEE410022P2脉冲输入卡件
通道值格式32位浮点16位整数或32位浮点高标度值（英制单位）四个标度参数的默认值取决于配置的量程类型和量程。每个范围和范围类型都有一组不同的默认值。注：如果高量程工程单位等于高量程A/D单位，而低量程工程单位则等于低量程A/D单位时，则禁用缩放。默认值为所选范围类型的A/D上限。低量程值（工程单位）默认值为所选量程类型的低A/D限值。必须低于高缩放值。高比例值（A/D单位）默认值为所选范围类型的高A/D限制。必须大于低缩放值。低量程值（A/D单位）默认值为所选量程类型的低A/D限值。11.2.3.2.1输入缩放：ALG626和ALG628默认情况下，模块将其配置范围的整个范围内的电压或电流输入转换为CPU的浮点值。例如，如果通道的量程为4至20mA，则模块报告4.000至20.000之间的通道输入值。通过修改四个信道缩放参数（低/高缩放值参数）中的一个或多个，可以针对特定应用更改缩放工程单位范围。缩放可以向PLC提供已转换为其物理含义的输入，或将输入值转换为更易于应用程序解释的范围。缩放始终是线性的，可以进行逆缩放。所有报警值适用于缩放的工程单位值，而不是A/D输入值。缩放参数仅设置两组对应值之间的线性关系。它们不一定是输入的限制。PACSystems*RX3i系统手册第12节GFK-2314T 2019年9月带HART通信的模拟模块503示例1对于电压输入，6.0伏表示每秒20英尺的速度，1.0伏表示每秒0英尺。此范围内的关系是线性的。对于本例，输入值应表示速度而不是电压。以下通道配置设置了此缩放：高标度值（Eng单位）=20.000低标度值，Eng单位=0.000高标度（A/D单位）=6.000低标值，A/D单位=1.000电压，A/D单位：1.000 6.000 0.000英尺/秒（工程单位）20.000图314：缩放示例ALG626/AL628对于本示例，1.0 Vdc至6.0 Vdc为正常电压范围，但是该模块将尝试为位于该范围之外的电压缩放输入。如果向通道输入10.0V的电压，模块将返回36.000的缩放通道值。对于超出可接受范围或无效的缩放输入，应用程序应使用警报或采取其他预防措施。示例2现有应用程序使用传统的模数（A/D）计数整数值。通过缩放和可选的16位整数输入选项，可以将通道配置为报告整数计数值。在此示例中，应用程序应将+10 Vdc解释为32000计数，将-10 Vdc解释为-3200计数。以下信道配置将将±10 Vdc输入信道缩放至±32000计数。信道值格式=16位整数高量程值（Eng单位）=32000.0低量程值（英制单位）=-3200.00高量程值，（A/D单位）=10.000低量程值参数（续）参数默认描述正变化率极限（英制单位）0.0每秒工程单位变化率，将触发正变化率警报。默认设置已禁用。与“采样率变化率”参数一起使用。负变化率限制（工程单位）0.0每秒工程单位的变化率，将触发负变化率警报。默认设置已禁用。与“采样率变化率”参数一起使用。变化率采样率0.0比较之间等待的时间（从0到300秒）。默认值0.0是在每次输入采样后进行检查。11.2.3.2.2变化率警报：ALG626和ALG628这些模块可以检测每秒工程单位的负变化率和正变化率。当任何一个变化率参数配置为非零时，模块将采用先前变化率样本和当前样本之间的工程单位差，然后除以样本之间的经过时间。
Channel Value Format 32-bit Floatingpoint 16-bit integer or 32-bit floating-point High Scale Value (Eng Units) The defaults for the four Scaling parameters depend on the configured Range Type and Range. Each Range and Range Type have a different set of defaults. Note: Scaling is disabled if both High Scale Eng. Units equals High Scale A/D Units and Low Scale Eng. Units equals Low Scale A/D Units. Default is High A/D Limit of selected range type. Low Scale Value (Eng Units) Default is Low A/D Limit of selected range type. Must be lower than the high scaling value. High Scale Value (A/D Units) Default is High A/D Limit of selected range type. Must be greater than the low scaling value. Low Scale Value (A/D Units) Default is Low A/D Limit of selected range type. 11.2.3.2.1 Input Scaling: ALG626 and ALG628 By default, the module converts a voltage or current input over the entire span of its configured Range into a floating-point value for the CPU. For example, if the Range of a channel is 4 to 20mA, the module reports channel input values from 4.000 to 20.000. By modifying one or more of the four channel scaling parameters (Low/High Scale Value parameters) from their defaults, the scaled Engineering Unit range can be changed for a specific application. Scaling can provide inputs to the PLC that are already converted to their physical meaning, or convert input values into a range that is easier for the application to interpret. Scaling is always linear and inverse scaling is possible. All alarm values apply to the scaled Engineering Units value, not to the A/D input value. The scaling parameters only set up the linear relationship between two sets of corresponding values. They do not have to be the limits of the input. PACSystems* RX3i System Manual Section 12 GFK-2314T Sept. 2019 Analog Modules with HART Communications 503 Example 1 For a voltage input, 6.0 volts represents a speed of 20 feet per second, and 1.0 volt represents 0 feet per second. The relationship in this range is linear. For this example, the input values should represent speed rather than volts. The following channel configuration sets up this scaling: High Scale Value (Eng Units) = 20.000 Low Scale Value (Eng Units) = 0.000 High Scale Value (A/D Units) = 6.000 Low Scale Value (A/D Units) = 1.000 Voltage (A/D Units) 1.000 6.000 0.000 Feet per Second (Engineering Units) 20.000 Figure 314: Scaling Example ALG626/ALG628 For this example, 1.0 Vdc to 6.0 Vdc is the normal voltage range, but the module will attempt to scale the inputs for a voltage that lies outside the range. If a voltage of 10.0V were input to the channel, the module would return a scaled channel value of 36.000. The application should use alarms or take other precautions for scaled inputs that are outside the acceptable range or invalid. Example 2 An existing application uses traditional analog to digital (A/D) count integer values. With scaling and the optional 16-bit integer input option, a channel can be configured to report integer count values. In this example, the application should interpret +10 Vdc as 32000 counts and -10 Vdc as -32000 counts. The following channel configuration will scale a ±10 Vdc input channel to ±32000 counts. Channel Value Format = 16-bit Integer High Scale Value (Eng Units) = 32000.0 Low Scale Value (Eng Units) = -32000.0 High Scale Value (A/D Units) = 10.000 Low Scale Value (A/D Units) = -10.000 Voltage -10,000 +10,000 -32,000 Counts 32,000 Figure 315: Scaling Example ALG626/ALG628 PACSystems* RX3i System Manual Section 12 GFK-2314T Sept. 2019 Analog Modules with HART Communications 504 Channel Parameters (Continued) Parameter Default Description Positive Rate of Change Limit (Eng Units) 0.0 Rate of change in Engineering Units per Second that will trigger a Positive Rate of Change alarm. Default is disabled. Used with “Rate of Change Sampling Rate” parameter. Negative Rate of Change Limit (Eng Units) 0.0 Rate of change in Engineering Units per Second that will trigger a Negative Rate of Change alarm. Default is disabled. Used with “Rate of Change Sampling Rate” parameter. Rate of Change Sampling Rate 0.0 Time to wait between comparisons (from 0 to 300 seconds). Default of 0.0 is to check after every input sample. 11.2.3.2.2 Rate of Change Alarms: ALG626 and ALG628 These modules can detect both Negative Rate of Change and Positive Rate of Change in Engineering Units per Second. When either Rate of Change parameter is configured to be non-zero, the module takes the difference in Engineering Units between the previous rate of change sample and the current sample, then divides by the elapsed time between samples.
