Shenzhen JHA Technology Co., Ltd is one of the leading manufacturers of hardened Ethernet, PoE, and fiber connectivity products specifically designed for harsh and demanding environments.





What is Loopback?

Loopback test is a test method, usually used to check and analyze port or line problems. It is through the process that the signal sent from the communication device returns (loopback) to the original place to diagnose whether the device is operating normally or to determine the location of the failed node in the network.

When the fault phenomenon can be preliminarily judged to be a line problem, it usually starts from a device at one end, loops back to this device from the nearest node, and gradually expands to further nodes and further nodes. Different nodes loop back to the same device to determine which two nodes have problems. This method is called segmented loopback test.

​How to debug the industrial switch port

1. Simplex loopback test

① Insert a duplex optical module into the switch.

②Use an optical fiber loopback module or a simplex optical fiber jumper to form a loop to connect the transmitting end and receiving end of an optical module to detect whether the parameters of the switch port and the optical module are normal.

③ Check the parameters and debug.

2. Duplex loopback test

① Insert two duplex optical modules into the industrial switch.

② Then use two optical fiber loopback modules or a duplex optical fiber jumper to form a loop to connect the two optical modules, and check whether the transmission rate of the optical module matches the operating rate of the switch port and whether the connection is normal.

③ Check the parameters and debug.