Detailed explanation of the role and function of RS485 hub

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Detailed explanation of the role and function of RS485 hub [Copy link]

RS485 hub is a bus split hub designed to meet the requirements of RS-485 large system bus form in complex communication environment. It adopts bus hanging connection mode, does not support star connection, but can provide RS-485/422 star connection mode through special design, thus changing the original single bus structure and bringing great convenience to network structure engineering construction.

The main functions of the RS485 hub include:

1. Expand the number of nodes: The RS485 bus itself can support up to 32 nodes, but the number of nodes on the bus can be further expanded by using a hub. The hub divides the bus into several branches, each of which can be connected to multiple RS485 devices, thereby expanding the number of bus nodes. Some hubs, such as the DT-9024I 485 4-port hub, can support 256 RS485 nodes per group, and the theoretical value of four groups is 1024 nodes.

2. Extend the communication distance: The transmission distance of RS485 bus is generally 1200 meters, but the use of RS485 hub can increase the ability of electrical isolation and signal amplification on the bus, thereby extending the transmission distance of the bus. The communication distance of some hubs can even exceed 3000 meters.

3. Electrical isolation: RS485 hubs usually have electrical isolation function, which can isolate the ground potential between different branches, thereby avoiding the influence of ground potential interference on communication quality. This helps to improve the anti-interference ability of the bus and ensure the reliability of communication. For example, some hubs provide 2.5KVrms or more than 3KV photoelectric isolation for all RS-485 interfaces, as well as transient voltage suppression TVS, and 600W protection for each line, which effectively solves the transmission problems caused by external lightning surges and ground potential differences.

4. Signal enhancement: RS485 hub can provide signal amplification and attenuation capabilities, so that the signal quality remains stable during the transmission process. The signal amplification function can enhance the strength of the signal and make the signal transmission range farther; while the attenuation function can effectively suppress signal interference and improve signal quality.

5. Other functions: RS485 hub also has functions such as short circuit and open circuit protection, data flow control, and data anti-collision protection, all of which help to improve the reliability and stability of the communication system.

In summary, RS485 hub plays an important role in industrial automation, distributed control systems and other fields. It can solve many practical engineering problems, such as expanding the number of nodes, extending the communication distance, isolating interference and enhancing signals.

RS485 Hub Product Introduction

RS485 hub is a bus split hub designed to meet the requirements of RS-485 large system bus form in complex communication environment. RS485 hub series products E810-R12 , E810-R14, E810-R18 correspond to 1-way RS-485 to 2/4/8-way RS-485 isolated repeater (HUB). RS485 hub is a communication device that supports 1-way RS-485 master station equipment and 1-way or multiple-way RS-485 slave station equipment. RS485 hub is suitable for comprehensive RS485 communication systems such as automation control system, monitoring system, alarm, access control system, IC card charging, meter reading, one-card pass, parking lot charging, etc.