5X00070G02模块备件

5X00070G02

22-8.1座位、后座和后退
座椅和后座功能相似，但座椅关闭
阀门，后座打开阀门。因此，仅描述了座椅。
撤退是一种反饱和功能。重要的是要记住，当RSR伺服
输出接近0伏，阀门处于静止状态。当伺服输出从
中点，阀门移动到所需位置，伺服输出返回到near
0伏。
退避是在就座后发生的一种特征。它是高度可编程的。
当目标位置小于座位限制时，RSR进入座位模式。在这个
模式RSR希望尽快关闭阀门。它通过驾驶来实现这一点
输出在阀门关闭的方向上难以到达导轨。
定时器到期后（ReturnHoldt）以及阀门位置关闭后，发生后退
到达RSR想要的位置（ABS|目标反馈|<posErrorRetreat）。当阀门
后退时，伺服输出从导轨返回到编程值（exitSeatVal）
预定义速率（后退速率）。
IPU-247 15
艾默生过程管理专有2C类
在典型情况下，用户将确定使伺服滑阀为零所需的电压；
i、 克服机械偏置调节。假设该值为–200 mV
然后，用户将exitSeatVal设置为–200 mV，再加上以下方向的任意量：
阀门关闭，可能为100 mV。因此，用户将exitSeatVal设置为–100 mV。此外，
假设用户将其他相关常数保留为其默认值。什么时候
进入座椅，伺服输出变为+10伏，并将保持至少10伏
秒。当10秒定时器到期时，以及当位置反馈在2
目标位置的百分比（可能为0），伺服输出从10伏变为–100 mV
每秒10%。10伏约为输出范围的50%，因此伺服输出将返回
5秒后降至–100 mV。在–100 mV时，伺服滑阀释放少量流体
从而关闭阀门。
如果目标位置变高，从而将RSR从座位上移除，伺服输出
将随时可用于开始m

5X00070G02
 

5X00070G02

22-8.1 SEATING, BACKSEATING, AND RETREAT Seating and BackSeating are similar functions, with the exception that Seating closes the valve, and BackSeating opens it. Therefore, only Seating is described. Retreat is an anti-windup function. It is important to remember that when the RSR servo output is near 0 volts, the valve is stationary. When the servo output moves away from the midpoint, the valve moves to the desired position, and the servo output goes back to near 0 volts. Retreat is a feature that occurs after Seating. It is highly programmable. When the target position is less than seatLimit, the RSR goes into a seating mode. In this mode the RSR wants to close the valve as fast as possible. It accomplishes this by driving the output hard to the rail in the direction of valve closure. Retreat occurs after a timer has expired (retreatHoldT), and once the valve position is close to where the RSR wants it to be (ABS|Target-Feedback| < posErrorRetreat). When a valve retreats, the servo output goes from the rail to a programmed value (exitSeatVal) at a predefined rate (retreatRate). IPU-247 15 Emerson Process Management Proprietary Class 2C In a typical scenario, the user would determine the voltage required to null the servo spool; i.e., overcome the mechanical bias adjustment. Let,s assume the value is –200 mV. The user would then set exitSeatVal to –200 mV plus an arbitrary amount in the direction of valve closure, 100 mV perhaps. So, the user would set exitSeatVal to –100 mV. Also, assume the user leaves the other associated constants to their default values. When seating is entered, the servo output goes to +10 volts and will remain there for at least 10 seconds. When the 10 second timer expires, and when position feedback is within 2 percent of the target position (probably 0), the servo output ramps from 10 volts to –100 mV at 10% per second. Ten volts is about 50% of output range, so the servo output would return to –100 mV after 5 seconds. At –100 mV, the servo spool is letting a small amount of fluid escape, thus closing the valve. If the target position went higher, thus removing the RSR from seating, the servo output would be readily available to begin to m