Click↑↑Technical Training, follow and pinto subscribe for free long-term
180,000+Industrial control professionals follow this WeChat platform: technical sharing, learning exchange, industrial control videos
After establishing RS-485 communication between the inverter and PLC, commands sent by the PLC via the communication cable can be received. If multiple inverters are connected to the PLC via RS-485, each inverter must be assigned a station number (using parameter Pr. 117, 0~31). When the PLC sends command data to a specific inverter, the beginning of the data will be the station number.
Advantages: Simple hardware, lowest cost, can control up to 32 inverters
Disadvantages: High programming workload
1. RS-485 Communication Connection of a Single Inverter and PLC
When connecting, the sending terminals (+/-) of one device should connect to the receiving terminals (+/-) of the other device, and the receiving terminals (+/-) should connect to the sending terminals (+/-) of the other device.
Appearance and installation of the 485BD communication board
2. RS-485 Communication Connection of Multiple Inverters and PLC
This allows one PLC to control the operation of multiple inverters
Points to note when connecting the inverter and PLC:
(1) The PLC itself should be grounded according to the specified wiring standards and grounding conditions, and care should be taken to avoid using a common grounding line with the inverter, keeping the two as separated as possible during grounding.
(2) When the power supply conditions are not good, noise filters, reactors, and noise reduction devices should be connected to the power lines of the PLC’s power module and input/output modules. Additionally, if necessary, corresponding measures should also be taken on the input side of the inverter.
(3) When the inverter and PLC are installed in the same control cabinet, the wires related to the inverter and those related to the PLC should be separated as much as possible.
(4) Use shielded cables and twisted pairs to improve the level of noise interference.
Source: Internet, copyright belongs to the original author, please remove if infringed
Click↓Read the original textFree learning of electrical knowledge such as electricians and PLC!