sequential (73) RJ45 (protocol) center tap (clock line)
https://kamchihau.blogspot.com/2023/07/blog-post.html . Ref: https://chihaukam.blogspot.com/2025/11/miuson-is-person-in-this-link.html?m=1 . . . . . John : See the 1st picture. When receive is at Down cycle, transmit is at Up cycle. Me: Ok. . John : See the 2nd picture. When the Transmission is at Up cycle, the direction current's flow of Tx+ is clear. However, the direction of current's flow of Tx- is unclear. Me: Why ? John: Because, it's a common mode which block the current's flow of TX -1. Me: Same thing. When Transmit is at the Up Cycle, the Receive is at the Down cycle. While the Receive is at the down cycle, the current flow of RD+ is clear but the current flow of RD- is unclear because of the common mode.