1, system introduction:

Siemens S7-400H is adopted on site. The DCS system monitors and controls the operation of the whole production line. Two sets of S 120 as Profibus of DCS system? DP？ The slave station controls two sets of ram respectively. At the same time, in order to ensure the reliability of the system, local and remote switching functions are set up. In remote working mode, position control is carried out, and Profibus is used in DCS? DP communication, send the target position value S 120, and control the flow gate to rise or fall.

2. Hardware configuration:

The control unit of S 120 is CU3 10-2DP, and the power unit is PM340, which matches Siemens 1FT7 high-performance motor. CU3 10-2？ DP control unit is designed for? SINAMICS？ The communication and open/closed loop control functions of S 120(AC/AC) are combined with the power module PM340 to form a powerful single-axis driver.

3. Electrical schematic diagram

Using the IO point integrated by CU3 10-2DP itself, the runner gate can be completely separated from the control of DCS, and local control can be realized. At the same time, CU3 10-2DP itself also integrates DP communication interface, which can realize remote control of runner gate through DCS.

4. System debugging:

Using MDI (Manual Setting Input) function in S 120 basic positioning function, complex positioning function can be easily realized through external system. MDI has two working modes, speed mode and position mode, which can be switched online by parameter P2653. When P2653 is 0, it is the speed mode; P2653 is in position mode at 1. Speed mode means that the shaft runs according to the set speed, acceleration and deceleration, regardless of the actual position of the shaft. Position mode means that the shaft runs according to the set position, speed and acceleration and deceleration. The position pattern can be divided into absolute position (P2648= 1) and relative position (P2648=0). In this project, the relative position mode of MDI is used when switching to DCS remote control, and the speed mode of MDI is used when switching to local control.

5. It should be noted that:

The basic positioning function of S 120 mainly includes the following contents:

1, inching: used to manually move the shaft and press the button to make the shaft run to the target point.

2. Reset/Reference: used to define the reference point of the shaft or return to zero during operation.

3. Limit: used to limit the speed and position of the shaft, including soft limit and hard limit.

4, program steps (traversal? Block):? ***64 program steps, which can automatically and continuously execute a complete program, also? Can be performed in one step.

5. Direct setpoint input/manual setpoint input (direct? Set point? Input/MDI): target position and running speed? The temperature can be controlled by the upper computer in real time.

There are three zeroing methods in S 120:

●? Set the reference point directly (set? Reference):? It can be used in any encoder.

●? Active zeroing (reference? Point? Method):? Mainly refers to the incremental encoder.

●? Dynamic zeroing (flying? Reference): Can be used for any encoder.

A more detailed explanation and process analysis can be found in official website.