Control ladder diagram of experimental loop

Ladder network design Based on the above analysis, the control ladder diagram in the speed switching loop
experiment can be written, as shown in the figure. 'j:
    (4): ÷Conclusion In the detachable hydraulic test bench, using PLC control system to replace
the traditional control method can overcome the poor reliability,
inconvenient control and slow response of the relay contact control system. However, its advantages are reflected in the following aspects:
    1) PLC control is programmable control and has good flexibility. When the experimental project is changed
, the hardware equipment controlled by PLC can remain unchanged, and only the corresponding application program needs to be changed
. Can.
    2) PLC control has high reliability and is adaptable to the experimental environment.
    3) PLC control has the characteristics of small size and light weight, and it is easy to realize a mechanical, electrical and
hydraulic integrated control device.
    4) PLC control function is perfect. In addition to the general starting quantity, analog input and output
and error control functions, it can also realize functions such as human-machine dialogue, recording and display, which is especially
suitable for the requirements of a detachable hydraulic test bench.
  Therefore, in the design of transforming the traditional hydraulic test bench and the new hydraulic test bench. PLC control method has important application value. on the other
hand. PLC -controlled experimental benches are also widely used in teaching, which can provide students with experimental
conditions for the comprehensive application of mechanical, electrical, and hydraulic knowledge, and are conducive to cultivating students' ability to analyze and solve problems.