RJ45 interface pin definition (various interface pin definitions)

The following is the circuit diagram of [RJ45 interface pin definition (various interface pin definitions)]

RJ45 interface signal definition, and network cable connector signal arrangement

Ethernet 10/100Base-T interface:
Pin Name Description
1 TX+ Tranceive Data+ (signal +)
2 TX- Tranceive Data- (Signal-)
3 RX+ Receive Data+ (receive signal +)
4 n/c Not connected (empty foot)
5 n/c Not connected (empty foot)
6 RX- Receive Data- (receive signal -)
7 n/c Not connected (empty foot)
8 n/c Not connected (empty foot)

Ethernet 100Base-T4 interface:
Pin Name Description
1 TX_D1+ Tranceive Data+
2 TX_D1- Tranceive Data-
3 RX_D2+ Receive Data+
4 BI_D3+ Bi-directional Data+
5 BI_D3- Bi-directional Data-
6 RX_D2- Receive Data-
7 BI_D4+ Bi-directional Data+
8 BI_D4- Bi-directional Data-

1 white/orange
2 orange/white
3 white/green
4 blue/white
5 white/blue
6 green/white
7 white/brown
8 brown/white

Note: The RJ45 interface uses differential transmission. tx+ and tx- are a pair of twisted pairs. Together, they can reduce interference.
Serial port and parallel port interface definition

The difference between the parallel port and the serial port is that the way of exchanging information is different. The parallel port can transmit information through 8 data lines at the same time, one byte is transmitted at a time; and the serial port can only transmit one bit of data with one line, each time. Transfer one bit of a byte. The parallel port is significantly faster than the serial port because it transmits more information at the same time, but the serial port can be used for data transmission farther than the parallel port.

1, 25 pin parallel port jack function:

Pin function pin function

1 strobe (STROBE low level) 10 acknowledgment (ACKNLG low level)

2 Data Bit 0 (DATAO) 11 Busy (BUSY)

3 data bit 1 (DATA1) 12 paper (PE)

4 Data Bit 2 (DATA2) 13 Select (SLCT)

5 Data Bit 3 (DATA3) 14 Word Wrap (AUTOFEED Low)

6 Data Bit 4 (DATA4) 15 Error View (ERROR Low)

7 Data Bit 5 (DATA5) 16 Initialized to (INIT Low)

8 Data Bit 6 (DATA6) 17 Select Input (SLCTIN Low)

9 Data Bit 7 (DATA7) 18-25 Ground Line (GND)

2. The typical representative of the serial port is the RS-232C and its compatible jacks, which are available in 9-pin and 25-pin versions. The 25-pin serial port has a 20mA current loop interface function, which is implemented with 9, 11, 18, and 25 pins. Its pin functions are as follows:

Pin function pin function

1 not used

2 Send data (TXD) 11 Data transmission (1)

3 Accepted data (RXD) 12-17 Unused

4 Request to Send (RTS) 18 Data Receive (+)

5 Clear Send (CTS) 19 Unused

6 Data Ready (DSR) 20 Data Terminal Ready Ratio (DTR)

7 Signal Ground Line (SG) 21 Not used

8 Carrier Detect (DCD) 22 Ringing Spirit (RI)

9 Send back (+) 23-24 Unused

10 unused 25 receive back (1)

Pin function of the 9-pin serial port:

Pin function pin function

1 Carrier Detect (DCD) 6 Data Ready (DSR)

2 Accept Data (RXD) 7 Request to Send (RTS)

3 Send data (TXD) 8 Clear send (CTS)

4 Data Terminal Ready (DTR) 9 Ringing Indicator (RI)

5 signal ground (SG)

(Editor: Circuit Diagram)