3.通过比较“内部”的IntCalcSPLo和IntCalcSPHi值与(HMI)用户指定的SPLo和SPHi值，确定SP限是否被送到SMOCPro内核。被送往内核的实际SPs是处于最保守的用户输入设定点限和内部计算限之间。
值得一提的是，通常情况下不会超出用户输入的SP限。但如果当前SP值碰巧位于用户设定限外，通常提供的计算SP限将以最大允许变化率（Max Move Size最大动作幅度）将MV驱动回允许区域。
从图1可以看出，如果dSPdVLo和dSPdVHi值选择过小，内部计算的IntCalcSPLo和IntCalcSPHi限近似值可能会大大偏离真实限。在图中的计算我们高亮了相关参数，其中用户必须输入的需要值用红色块表示，而对某一给定OP值由SMOCPro计算出的值则用蓝色块表示。下列指南给出了如何设置dSPdVLo/Hi参数的内容。
| 用户指定输入| |
| ------------- |:-------------:| :-----:|
| OPLo| 阀门操作低限（开度）。|
| OPHi| 阀门操作高限（开度）。|
| SPLo| 最小SP值。|
| SPHi | 最大SP值。|
| dSPdVLo | 在阀门操作低限时，阀位(OP)与操作设定点（SP）间的增益关系。|
| dSPdVHi | 在阀门操作高限时，阀位(OP)与操作设定点（SP）间的增益关系。|
|SMOCPro 计算值||
| ------------- |:-------------:| :-----:|
|dSPdV |在当前操作点阀位值(OP)时阀位(OP)与操作设定点(SP)之间的增益关系。|
|IntCalcSPLo |内部计算的当给定OPLo时最小可达到SP值。|
|IntCalcSPHi |内部计算的当给定OPHi时最大可达到SP值。|
|CalcSPLo |对于给定传递到内核的OPLo，计算最小可到达的SP值。|
|CalcSPHi |对于给定传递到内核的OPLo，计算最大可到达的SP值。|
SMOCPro dSPdV的数学解释
我们现在提供dSPdV计算的基本步骤。算法的第一步是根据当前的OP, dSPdV计算OP对SP的增益。该值通过用户指定dSPdVLo/Hi和OPLo/Hi值的内插法确定。
一旦dSPdV已经确定，下一步就是计算“内部”SP限。计算按照下列关系式进行：
原文：
- Determine the SP limits to be sent to the SMOCPro kernel by comparing the “internal” IntCalcSPLo and IntCalcSPHi values to the (HMI) user-specified SPLo and SPHi values. The actual SPs sent to the kernel are the most conservative between the user-entered set point limits and the limits calculated internally.
It is worth mentioning that the SP limits entered by the user are never exceeded by the routine. Also, if the current SP value happens to be outside the user-set limits, the routine provides calculated SP limits to drive the MV back towards the allowed region, at the maximum allowable rate-of-change (Max Move Size).
In Figure 1, it can be seen that the internally calculated IntCalcSPLo and IntCalcSPHi limits are approximations that can be quite far off the real limits if the dSPdVLo and dSPdVHi values are chosen too small. We highlight the parameters involved in the calculation in the figure, where the required values that the user must specify are shown in red blocks and the values that are calculated by SMOCPro for a given OP value are encased in blue blocks. Guidelines are given below on how to set the dSPdVLo/Hi parameters.
| User-specified Inputs| |
| ------------- |:-------------:| :-----:|
| OPLo | The valve’s low (opening) operating limit.|
| OPHi | The valve’s high (opening) operating limit.|
| SPLo | Minimum SP value.|
| SPHi | Maximum SP value.|
| dSPdVLo | The valve position (OP) to manipulated set point (SP) gain relationship at the valve’s low operating limit.|
| dSPdVHi | The valve position (OP) to manipulated set point (SP) gain relationship at the valve’s high operating limit.|
| SMOCPro calculated Values| |
| ------------- |:-------------:| :-----:|
| dSPdV | The valve position (OP) to manipulated set point (SP) gain relationship at the current valve (OP) operating point.|
| IntCalcSPLo | Internally calculated minimum achievable SP value for the given OPLo.|
| IntCalcSPHi | Internally calculated maximum achievable SP value for the given OPHi.|
| CalcSPLo | Calculated minimum achievable SP value for the given OPLo passed to the kernel.|
| CalcSPHi | Calculated maximum achievable SP value for the given OPHi passed to the kernel.|
**SMOCPro dSPdV Mathematical Explanation **
We now provide the basic steps of the dSPdV calculation. The first step in the algorithm is to calculate the OP to SP gain to be used for the current OP, dSPdV. This value is determined using an interpolation of the user-specified values dSPdVLo/Hi and OPLo/Hi.
Once dSPdV has been determined, the next step is to calculate the “internal” SP limits. The following relationships show the calculation:
2016.7.3
