Festo FESTO releases D to the roller lever valve at this time, then the gas from C to D flows and empties, and the pressure of the lower chamber is very small. Close the D port, then D has no gas, and B has gas but no flow, as shown in Figure 13.0d; similarly, at this time, close D again, and the components will still maintain this state. According to the two basic components of the three-door and four-door above , it can form common OR gates, AND gates, NOT gates, memory elements, etc. in logic circuits. 13. 13.2.4.3 Logic element selection The pressure change of the air source used in the pneumatic logic control system must ensure the normal operation of the logic element. The switching pressure required for switching the range and output terminal, the output flow and response time of the logic element can be selected according to the system requirements with reference to the relevant data when designing the system. The components are arranged in a centralized manner for centralized management. Since there is a certain delay in the transmission of the signal, the signal sending point (such as a travel switch) and the receiving point (such as a component) cannot be too far apart. Generally speaking, no more than a few Ten meters. When the logic elements are to be connected in series with each other - there must be enough flow, otherwise it may not be able to push the next-level element. In addition, although the high-voltage logic element does not require high air source filtration. However, when using the filtered air source, it must be Do not allow the air supply with oil mist to enter the logic element. 16 Pneumatic proportional, servo, digital control valve ( 13.3 Pneumatic proportional, servo, digital control valve