What's the steps for replacing the PLC of molding machine?

The steps for replacing the rubber molding machine PLC need to comprehensively consider multiple aspects such as equipment compatibility, 

program migration, peripheral equipment adaptation, and system debugging.

 The following are the key steps and precautions based on the search results:

1. Original PLC program backup and password processing**

- **Program backup**: Before disassembling the old PLC, the original program must be backed up through programming software (such as STEP 7, TIA Portal, etc.). 

If the PLC is password protected, you need to contact the equipment supplier or manufacturer to obtain the password, 

otherwise you cannot read or modify the program.

- **Storage medium check**: For PLCs that use MMC cards or EEPROM storage (such as Siemens S7-300), 

you need to ensure that the storage card is intact to avoid program loss or damage. If the storage medium fails, you need to replace and rewrite the program.

2. New PLC selection and compatibility evaluation**

- **Model replacement**: Select a functionally compatible replacement model based on the original PLC model. For example, Siemens S7-300 can be replaced with S7-1500 or ET 200MP series. Pay attention to whether the hardware interface, I/O points, communication protocol, etc. match.

- **Software adaptation**: The new PLC may require updated programming software (such as TIA Portal), and it is necessary to ensure that the original program can run on the new platform. Some old instructions or modules need to be adjusted or replaced.

3. Hardware installation and wiring**

- **Power connection**: Strictly distinguish the power supply mode (such as 24VDC or 220VAC), incorrect wiring may cause damage to the PLC.

- **I/O module migration**: Connect the original I/O modules to the new PLC one by one, and check whether the wiring terminals match. Pay special attention to whether the address allocation of analog modules (such as temperature and pressure sensors) is consistent with the new system.

- **Communication interface configuration**: If the original system includes HMI (human-machine interface) or inverter, the communication protocol (such as PPI, Modbus RTU) needs to be reconfigured to ensure that the new PLC is compatible with existing equipment.

4. Program migration and debugging**

- **Program import**: Import the backup program into the new PLC and check whether there are any instruction incompatibility issues caused by version differences. For example, the project file needs to be converted when migrating the S7-300 program to the S7-1500.

- **Parameter adjustment**: Adjust the timer and counter parameters in the program according to the new hardware characteristics, and calibrate the analog input/output (such as temperature control PID parameters).

- **Function test**: Test key functions (such as mold closing action, heating control) in steps, and troubleshoot logical errors through monitoring tools (such as PLC online diagnosis).

5. Peripheral equipment inspection and optimization**

- **Sensor and actuator verification**: Check whether peripheral equipment such as proximity switches and solenoid valves are working properly. For example, a proximity switch failure may cause abnormal mold closing speed, which requires adjustment of the position or replacement.

- **Power supply and grounding optimization**: Ensure that the system is grounded reliably to avoid electromagnetic interference causing PLC program confusion or communication interruption.

- **Energy-saving function integration**: If replaced with a new PLC (such as a model that supports Ethernet communication), the temperature control algorithm can be optimized or the energy consumption monitoring function can be added to improve the efficiency of the vulcanizer.

6. System integration and document archiving**

- **Full process testing**: Simulate the production environment to run the equipment and verify the stability of continuous operation. Focus on multi-tasking capabilities (such as controlling heating and pressure at the same time).

- **Operation training**: Update the operation manual and train personnel to master the new PLC interface and fault diagnosis methods (such as locating problems through HMI alarm information).

- **Maintenance records**: Archive program versions, hardware configurations, and debugging logs for subsequent maintenance or re-upgrades.

Notes**

- **Spare parts support**: If the old model PLC has been delisted (such as Siemens S7-300), it is necessary to confirm the spare parts supply cycle and purchase key modules in advance if necessary.

- **Anti-interference measures**: Add shielding layers or filters near high-voltage equipment (such as heating pipes) to prevent interference with PLC signals.

- **Regulatory compliance**: Ensure that the new system meets safety standards (such as electrical isolation and emergency shutdown functions).

Through the above steps, the PLC replacement of the vulcanizer can be completed systematically, and the reliability and intelligence level of the equipment operation can be improved. The specific operation needs to be combined with the equipment manual and the supplier's technical support.