Pneumatic valve (PROVOX regulator of positive and negative role in regulating 3)

a control circuit of the controller used positive and negative effect, is the common sense that self-control professionals, there is no any fresh content. But Fisher - PROV Rosemount companies ( XDCS products used by this concept is different. Must know the difference between it and could form a correct control circuit on the DCS. This concept is the core of introduced a IVP ( ImpliedValvePosition is suggested that the concept of the pneumatic valve position. With this. The concept of IVP, replace the concept of the traditional controller output signal, and its regulator the concept of positive and negative effect is different. Always represent the significance of this IVP command by this controller output signal to adjust the opening of pneumatic valve value, but it is not to adjust the pneumatic valve pneumatic valve position transmitter real measured by pneumatic valve opening, but this section modulator output signal to adjust the pneumatic valve, after the opening of the pneumatic valve should have values. Therefore, it is called implied ( Implied pneumatic valve position. To clear up the concept of the IVP, regulator new concept of positive and negative effect it is not hard to understand. This is action, is when the deviation of regulator ( Measurement is positive, set negative increases, the required command by this controller adjust the opening of pneumatic valve also increases; Conversely, when the deviation of the regulator increase, and required the regulator command control pneumatic valve opening decreases, and it is counterproductive. By this definition, this concept to the original concept of traditional way of thinking much more simple and clear. Determine the control circuit in the regulator of the positive and negative effect is very convenient, fast. The prominent feature of the concept, that is, when determining circuit regulator in the positive and negative effect, adjust the pneumatic valve 'more open' ( FC, said gas open and 'add close' ( Xsl-fo, habit according to the performance of the closed type to put aside the gas, so the idea is simple. Of course, in actual control process, the adjustment of pneumatic valve FC and FO performance are not allowed to put aside, it is a complex problem is decomposed into two simple questions to deal with. Here, the regulating pneumatic valve FC and FO performance is treated as a parameter of the controller itself, namely when the regulator configuration, must fill in the command by the regulator to adjust the pneumatic valve is a 'more open' or 'add close' ( The content of the FC or FO. Regulator the FC or FO information, that is the signal processing in internal - — For FO reverse, not reverse with FC. Such guarantees the send to regulate the correctness of the pneumatic valve command signal, also ensures that the operator see on the screen of the regulator of IVP signal always represent its command to adjust the opening of pneumatic valve should be - — Pneumatic valve, pneumatic valve fully open, O % seated. Make operators do not have to bear in mind that each adjust the FC and FO of pneumatic valve, control personnel from the structure of the control loop can be easily determine the positive role of regulator. This kind of concept, for only command a regulating pneumatic valve ( Or the output signal to a subsequent unit - — Controller, the control system of auxiliary units such as advantage is obvious; And for a regulator command more than one pneumatic valve adjustment, may bring some trouble, occur two ( Do not match the FC or FO several regulating pneumatic valve, or two ( A few request pneumatic valve on the regulator of the positive and negative effects and so on. For similar problems, the first to ensure that control function is correct; The first to adjust the FC and FO of pneumatic valve and regulator of the positive and negative effect, according to the characteristics of the control circuit, the operator's operation habit, will be subject to one of the pneumatic valve adjustment, fill in the regulator configuration function and regulation of the positive and negative FC and FO content of pneumatic valve. For other regulating pneumatic valve, although can't meet the FC in the regulator configuration and FO and the positive and negative effect of form a complete set, but must meet its control function in any other way is correct. PROVOX system is has many functions can meet the requirement. CP FST programming function to implement. Keywords:
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