What is the working process of the shrink machine？Introduction to switch control of shrink machineWhat do you have？How can we ensure that our machines can produce better after we have purchased the machine？What are the control buttons of the shrink machine？What does an on/off button do？
     There are two kinds of open-loop control: one is program control, and the other is proportional control。
　　Program control means that once the control command is started, it will be controlled according to the predetermined program, so that the moving parts can move according to the required speed, acceleration control or trajectory until the control task is completed。
　　Proportional control is that one pulse output (control quantity) tracks the change of another input quantity, also known as follow-up control or synchronous motion。The biggest advantage of open-loop control is simplicity, fast response speed, and no problem of system instability。Therefore, NC also uses open loop control。
　　Open loop control is used for positioning and motion control with single axis, double axis, and multi-axis。Minicomputers are mostly used for single-axis or dual-axis control。
　　Single-axis position control, single-axis acceleration and deceleration position control, single-axis multi-stage position control and multi-axis coordinated motion control are discussed in the following sections。
　　On a single axis (a certain coordinate), when the work order is issued, the component can be made to complete the displacement of the specified amount (the number of pulses) at the specified speed (the specified pulse frequency), that is, the "position control" here.。
　　The hardware of such a system can be a small PLC, a stepper motor and supporting facilities and moving parts。