B10过程输出变量视图
Process Output Variable（过程输出变量）数据在选中的控制器下的POV视图下显示和输入。
Process Output Variable（过程输出变量）视图可在“ENG”和“OPE”两个模式下操作。
以下是ENG模式的HIS窗口。
查看
条目说明
需要由操作员和工程师输入的各个条目/参数如下所示。
| 条目| 描述| 操作员模式| 工程师模式|
| ------------- |:-------------:| -----:|
| Tag Name（位号名） | POV位号名。 | R| R|
| Tag Comment （位号描述）| POV的描述。| R | R|
| Measurement （测量值） | POV的测量值（该POV是从DCS读取的实际PV值）。| R | R|
| Bad Value（坏值） | TRUE表示该POV测量值的质量是坏的； FALSE表示该POV测量值的质量是好的。 | R| R|
| Disconnect（断开连接）| 当要将POV禁用，不让控制器使用时，选择TRUE。MEASUREMENT（测量值）将被完全忽略。 这在维护工作或特殊工艺操作条件时是有意义的。 当控制器要使用POV时，选择FALSE。 | R/W| R/W|
| Essential for Control（必要控制） | 当POV对于控制是必需时，选择TRUE。当POV对于控制不是必需时，选择FALSE （默认）。选择“TRUE”将有以下效果。 如果POV不可用时，则Execute Control（执行控制）将自动使控制器进入STANDBY（挂起）模式。| -| R/W|
| Maximum Time in Prediction（预测最大时间） | 当控制器在断开或不可用（例如，BAD值）POV的情况下执行延长的时间段。控制器将在内部继续预测POV值，但因为没有来自过程的反馈，该预测不可避免地会偏离实际过程值。为此，已经为每个必要的POV添加了检查，该检查仅允许该POV在设置为MAX TIME IN PREDICTION（最大预测时间）的有限周期内保持断开或不可用，之后控制器将被强制为STANDBY（挂起）。 对于非必需的POV，不执行该检查。这可以确保具有长时间测量问题的POV可以永久断开，直到问题解决。| -| R/W|
| Sample&Hold Signal（采样保持信号）| 指示它是连续（无扰动）还是采样和保持信号（脉冲重连）。| - | R/W|
| Impulse Factor (脉冲因子) | 用于过滤不可测量干扰的脉冲因子。| - | R/W|
原文：
B10. Process Output Variable View
Process Output Variable data are displayed and entered on the selected POV view of the selected controller.
Process Output Variable view has two operations modes such as “ENG” and “OPE”.
Following are the HIS windows for the ENG modes.
View
Description of items
Various items/parameters need to be entered by operator and engineers are described below.
| Item | Description | Operator mode| Engineer mode|
| ------------- |:-------------:| -----:|
| Tag Name | POV Tag Name | R| R|
| Tag Comment | POV’s Comment| R | R|
| Measurement | Measured value of POV (This is actually a PV value from DCS for this POV)| R| R|
| Bad Value| TRUE indicates quality of measurement for POV is bad. FALSE- indicates quality of measurement for POV is good. | R | R|
| Disconnect | TRUE- is selected when POV is to be disabled for use by the Controller. The MEASUREMENT will be totally ignored. This is of interest during maintenance work or special process operating conditions. FALSE- is selected when POV is to be enabled for use by the controller| R/W | R/W|
| Essential for Control| TRUE- is selected when POV is essential for control. FALSE -(Default) is selected when POV is not essential for control. Selection of “TRUE” provides following effect. If in case DV is not available then “Execute Control” routine will automatically put the controller into STANDBY mode.| -| R/W|
| Maximum Time in Prediction | It is not desirable for the controller to execute for a prolonged period with a disconnected or unavailable (e.g. BAD VALUE) POV. The controller will continue to predict the POV value internally, but without feedback from the process, this prediction inevitably wander away from the actual process value. For that reason, a check has been added for each essential POV which will allow only that POV to remain disconnected or unavailable for a finite period set as “MAX TIME IN PREDICTION” in minuets, after which the controller will be forced to “STANDBY” For a non-essential POV, this check is not carried out. This ensures that POV’s with long-term measurement problems can be permanently disconnected until problem is fixed.| -| R/W|
| Sample&Hold Signal| Indicates if it is a continuous (bumpless) or sample and hold signal (bump reconnection) | - | R/W|
| Impulse Factor | Impulse factor to filter unmeasured disturbances. | - | R/W|
2017.1.8
