HIMA F3117工控自动化卡件
（A/D单位）默认值为所选范围类型的A/D下限。9.10.4.3输入缩放：ALG608和ALG616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。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。以下信道配置设置了此缩放：PACSystems*RX3i系统手册第10节GFK-2314T 2019年9月模拟输入模块416高量程值（Eng单位）=20.000低量程值（英制单位）=0.000高量程值示例ALG608或ALG616对于本示例，1.0 Vdc至6.0 Vdc为正常电压范围，但模块将尝试为超出范围的电压缩放输入。如果向通道输入10.0 Vdc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。9.11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位整数高比例值（Eng单位）=32000.0低比例值（Eng单位）=-3200.0高比例值，（A/D单位）=10.000低比例值，A/D单位=-10.000电压-10000+10000-32000计数32000图287：缩放示例ALG608或ALG616 PACSystems*RX3i系统手册第10节GFK-2314T 2019年9月模拟输入模块417信道参数（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。
(A/D Units) Default is Low A/D Limit of selected range type. 9.10.4.3 Input Scaling: ALG608 & ALG616 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. 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: PACSystems* RX3i System Manual Section 10 GFK-2314T Sept. 2019 Analog Input Modules 416 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 286: Scaling Example ALG608 or ALG616 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 10.0 Vdc 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. 9.11 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 287: Scaling Example ALG608 or ALG616 PACSystems* RX3i System Manual Section 10 GFK-2314T Sept. 2019 Analog Input Modules 417 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.
