由于斜坡變量的不穩定性，智能向導測試應用程序提供了一個特殊的機制來處理斜坡變量，以便將其保持在控制之下，而相關聯的獨立變量仍然可以做階躍動作。
每個斜坡變量（真斜或偽斜）都將與由參數STRAMPMVS定義的MV列表相關聯。這些MV都被假定為對斜坡變量具有顯著的影響，可通過對應的模型曲線證明。
在階躍測試過程中，其中一個列表中的MV將作為活躍斜坡處理。這意味著將僅通過移動該MV來完成整定斜坡的過程。
活躍斜坡處理由參數STRAMPACTMV定義。然而，如果指定的活躍斜坡處理不可用（即它處于不在服務或壞狀態時），智能向導引擎將自動拾取列表中下一個可用的斜坡處理。
只有當斜坡變量以一定方式觸碰到上下限時，斜坡處理變量將啟動一個階躍。事情發生基于下列條件：
? 當前斜坡測量值在（STCVMAX - STCVDELTA）與（STCVMIN+ STCVDELTA）范圍之外，并且穩態預測值在（STCVMAX+ STCVDELTA）與（STCVMIN - STCVDELTA）范圍之外。
-或者-
? 當前斜坡測量值與穩態預測值都在STCVMAX~STCVMIN范圍之外。
當這種情況發生時，智能向導引擎將對該斜坡處理變量寫入一個階躍動作，階躍大小將通過使斜坡變量轉向并朝著規定斜率相反限制決定。
斜率由STRAMPRT參數定義：斜率越大階躍越大。不同于普通的MV，斜坡處理變量的測試信號沒有任何脈沖疊加。
一個應用程序中可以包含多個斜坡變量。當任一個MV的階躍影響到斜坡變量時，智能向導引擎將考慮這一影響，以及兼顧分配到該斜坡變量的斜坡處理能力。因此，斜坡處理變量將始終保留有足夠的空間用于必要時將斜坡環繞。
在智能向導應用中斜坡變量始終擁有較高的優先級。如果一個斜坡變量觸碰到限制，但移動斜坡處理變量可能會導致另一CV違反限制，那么智能向導引擎將依舊寫入斜坡處理動作以使斜坡返回。在這種情況下，為了避免其它CV違反約束太多，應用程序將使用STRAMPRT的十分之一，以代替原來整個需求斜率。
注：若智能向導應用處于TEST模式（包括TEST NO-PULSE）運行時，所有的斜坡變量都被視為非關鍵變量。只有所有測試組都不處于測試模式時，斜坡變量的原始設置才將得到遵守。
附原文：
Due to the unstable nature of a ramp variable, a SmartStep tester application provides a special mechanism to handle a ramp variable so that it will remain under control, while associated independent variables can still make step moves.
Each ramp variable (true or pseudo ramp) will be associated with a list of manipulated variables specified in parameter STRAMPMVS. These manipulated variables are assumed to have significant impact to the ramp variable, as evidenced in their model curves.
During the course of step testing, one of the manipulated variables in the list will become an active ramp handle. This means, this manipulated variable will be moved solely for the purpose of turning the ramp.
The active ramp handle is specified by parameter STRAMPACTMV. However, if the specified active ramp handle is not available (that is, it is out of service or has a bad status), the SmartStep engine automatically picks up the next available ramp handle in the list.
The ramp handle variable will initiate a step only when the ramp variable hits its upper or lower limit in a certain way. Occurences are based on the following conditions:
?If current ramp measurement is outside the range between (STCVMAX – STCVDELTA) and (STCVMIN + STCVDELTA), and the steady-state prediction is outside the range between (STCVMAX + STCVDELTA) and (STCVMIN - STCVDELTA).
-or-
?If both current ramp measurement and steady-state prediction are outside the range between STCVMAX and STCVMIN.
When this occurs, the SmartStep engine will make a step move on this ramp handle variable, and the step size will have such a value that the ramp variable will turn and move toward the opposite limit with a prescribed ramp rate.
The ramp rate is specified in parameter STRAMPRT: the larger the ramp rate the bigger the step size. Unlike a regular manipulated variable, a ramp handle variable does not have any pulses superimposed on its test signal.
There can be multiple ramp variables in an application. When stepping any manipulated variable that has impact on a ramp variable, the SmartStep engine will consider this impact, as well as taking into account the capability of the ramp handle assigned to this ramp variable. As such, the ramp handle variable will always reserve adequate room available to turn a ramp around when necessary.
A ramp variable is always treated in a higher priority in a SmartStep application. If a ramp variable hits a limit, but moving the ramp handle variable may cause another controlled variable to violate its limit, then the SmartStep engine will still move the ramp handle to turn back the ramp. In this case, only one tenth of STRAMPRT will be used, instead of the full requested ramp rate, in order to prevent the other controlled variable from violating its limit too much.
Note: When the SmartStep application runs in TEST mode (including TEST NO-PULSE), all ramp variables are treated as non- critical variables. The original setting for a ramp variable will be honored only after all testing groups are not in test mode.
2015.10.15
