EIA/TIA-568A and 568B pinouts

Pin T568A Pair T568B Pair 1000BASE-T Signal ID Wire T568A Color T568B Color Pins on plug face (socket is reversed)
1 3 2 DA tip Pair 3 Tip
white/green stripe
Pair 2 Tip
white/orange stripe
2 3 2 DA- ring Pair 3 Ring
green solid
Pair 2 Ring
orange solid
3 2 3 DB tip Pair 2 Tip
white/orange stripe
Pair 3 Tip
white/green stripe
4 1 1 DC ring Pair 1 Ring
blue solid
Pair 1 Ring
blue solid
5 1 1 DC- tip Pair 1 Tip
white/blue stripe
Pair 1 Tip
white/blue stripe
6 2 3 DB- ring Pair 2 Ring
orange solid
Pair 3 Ring
green solid
7 4 4 DD tip Pair 4 Tip
white/brown stripe
Pair 4 Tip
white/brown stripe
8 4 4 DD- ring Pair 4 Ring
brown solid
Pair 4 Ring
brown solid

RJ45 to balanced audio/XLR

Pin Analog signal AES/EBU T568A Color T568B Color Pins on plug face (socket is reversed)
1 L AES Pair 3 Tip
white/green stripe
Pair 2 Tip
white/orange stripe
2 L- AES- Pair 3 Ring
green solid
Pair 2 Ring
orange solid
3 R n/c Pair 2 Tip
white/orange stripe
Pair 3 Tip
white/green stripe
4 Gnd Gnd Pair 1 Ring
blue solid
Pair 1 Ring
blue solid
5 n/c n/c Pair 1 Tip
white/blue stripe
Pair 1 Tip
white/blue stripe
6 R- n/c Pair 2 Ring
orange solid
Pair 3 Ring
green solid
7 -15 -15 Pair 4 Tip
white/brown stripe
Pair 4 Tip
white/brown stripe
8 15 15 Pair 4 Ring
brown solid
Pair 4 Ring
brown solid


Power over Ethernet, IEEE 802.3af standards A and B

PINS on Switch T568A Color T568B Color  10/100 DC on Spares (mode B)   10/100 Mixed DC & Data (mode A)   1000 (1 Gigabit) DC & Bi-Data (mode B)   1000 (1 Gigabit) DC & Bi-Data (mode A) 
Pin 1 Pair 3 Tip
white/green stripe
Pair 2 Tip
white/orange stripe
Rx Rx             DC TxRx A TxRx A             DC
Pin 2 Pair 3 Ring
green solid
Pair 2 Ring
orange solid
Rx - Rx -              DC TxRx A - TxRx A -              DC
Pin 3 Pair 2 Tip
white/orange stripe
Pair 3 Tip
white/green stripe
Tx Tx             DC - TxRx B TxRx B             DC -
Pin 4 Pair 1 Ring
blue solid
Pair 1 Ring
blue solid
DC unused TxRx C             DC TxRx C
Pin 5 Pair 1 Tip
white/blue stripe
Pair 1 Tip
white/blue stripe
DC unused TxRx C -             DC TxRx C -
Pin 6 Pair 2 Ring
orange solid
Pair 3 Ring
green solid
Tx - Tx -             DC - TxRx B - TxRx B -             DC -
Pin 7 Pair 4 Tip
white/brown stripe
Pair 4 Tip
white/brown stripe
DC - unused TxRx D             DC - TxRx D
Pin 8 Pair 4 Ring
brown solid
Pair 4 Ring
brown solid
DC - unused TxRx D -             DC - TxRx D -


Ethernet crossover cables

Two pairs crossed, two pairs uncrossed
10BASE-T or 100BASE-TX crossover
Pin Connection 1: T568A
Connection 2: T568B
Pins on plug face
signal pair color signal pair color
1 BI_DA 3 Pair 3 Tip
white/green stripe
BI_DB 2 Pair 2 Tip
white/orange stripe
2 BI_DA- 3 Pair 3 Ring
green solid
BI_DB- 2 Pair 2 Ring
orange solid
3 BI_DB 2 Pair 2 Tip
white/orange stripe
BI_DA 3 Pair 3 Tip
white/green stripe
4 1 Pair 1 Ring
blue solid
1 Pair 1 Ring
blue solid
5 1 Pair 1 Tip
white/blue stripe
1 Pair 1 Tip
white/blue stripe
6 BI_DB- 2 Pair 2 Ring
orange solid
BI_DA- 3 Pair 3 Ring
green solid
7 4 Pair 4 Tip
white/brown stripe
4 Pair 4 Tip
white/brown stripe
8 4 Pair 4 Ring
brown solid
4 Pair 4 Ring
brown solid
Gigabit T568A crossover
All four pairs crossed
10BASE-T, 100BASE-TX, 100BASE-T4 or 1000BASE-T crossover (shown as T568A)
Pin Connection 1: T568A Connection 2: T568A Crossed Pins on plug face
signal pair color signal pair color
1 BI_DA 3 Pair 3 Tip
white/green stripe
BI_DB 2 Pair 2 Tip
white/orange stripe
2 BI_DA- 3 Pair 3 Ring
green solid
BI_DB- 2 Pair 2 Ring
orange solid
3 BI_DB 2 Pair 2 Tip
white/orange stripe
BI_DA 3 Pair 3 Tip
white/green stripe
4 BI_DC 1 Pair 1 Ring
blue solid
BI_DD 4 Pair 4 Tip
white/brown stripe
5 BI_DC- 1 Pair 1 Tip
white/blue stripe
BI_DD- 4 Pair 4 Ring
brown solid
6 BI_DB- 2 Pair 2 Ring
orange solid
BI_DA- 3 Pair 3 Ring
green solid
7 BI_DD 4 Pair 4 Tip
white/brown stripe
BI_DC 1 Pair 1 Ring
blue solid
8 BI_DD- 4 Pair 4 Ring
brown solid
BI_DC- 1 Pair 1 Tip
white/blue stripe
Gigabit T568B crossover
All four pairs crossed
10BASE-T, 100BASE-TX, 100BASE-T4 or 1000BASE-T crossover (shown as T568B)
Pin Connection 1: T568B Connection 2: T568B Crossed Pins on plug face
signal pair color signal pair color
1 BI_DA 2 Pair 2 Tip
white/orange stripe
BI_DB 3 Pair 3 Tip
white/green stripe
2 BI_DA- 2 Pair 2 Ring
orange solid
BI_DB- 3 Pair 3 Ring
green solid
3 BI_DB 3 Pair 3 Tip
white/green stripe
BI_DA 2 Pair 2 Tip
white/orange stripe
4 BI_DC 1 Pair 1 Ring
blue solid
BI_DD 4 Pair 4 Tip
white/brown stripe
5 BI_DC- 1 Pair 1 Tip
white/blue stripe
BI_DD- 4 Pair 4 Ring
brown solid
6 BI_DB- 3 Pair 3 Ring
green solid
BI_DA- 2 Pair 2 Ring
orange solid
7 BI_DD 4 Pair 4 Tip
white/brown stripe
BI_DC 1 Pair 1 Ring
blue solid
8 BI_DD- 4 Pair 4 Ring
brown solid
BI_DC- 1 Pair 1 Tip
white/blue stripe


Registered Jack (RJ) 11, 14, 25

Position Pair T/R ± RJ11 RJ14 RJ25 25-pair color code U.S. Bell System colors German colors Australian colors
1 3 T T3 Pair 4 Wire 1
white/green
Pair 3 wire 1
white
Pair 3 wire 1
violet
Pair 3 wire 1
orange
2 2 T T2 T2 Pair 2 Wire 1
white/orange
Pair 2 Wire 1 Old
black
Pair 2 ext. bell
green
Pair 2 ext. bell
red
3 1 R R1 R1 R1 Pair 1 Wire 2
blue/white
Pair 1 Wire 2 Old
red
Pair 1 wire A
white
Pair 1 wire B
blue
4 1 T T1 T1 T1 Pair 1 Wire 1
white/blue
Pair 1 Wire 1 Old
green
Pair 1 wire B
brown
Pair 1 wire A
white
5 2 R R2 R2 Pair 2 Wire 2
orange/white
Pair 2 Wire 2 Old
yellow
Pair 2 ground
yellow
Pair 2 ground
black
6 3 R R3 Pair 3 Wire 2
green/white
Pair 3 Wire 2
blue
Pair 3 wire 2
slate
Pair 1 Wire 1 Old
green


Registered Jack (RJ) 21/21X

Female RJ21 connector
Color Pin (Tip) Pin (Ring) Color
White/Blue 26 1 Blue/White
White/Orange 27 2 Orange/White
White/Green 28 3 Green/White
White/Brown 29 4 Brown/White
White/Slate 30 5 Slate/White
Red/Blue 31 6 Blue/Red
Red/Orange 32 7 Orange/Red
Red/Green 33 8 Green/Red
Red/Brown 34 9 Brown/Red
Red/Slate 35 10 Slate/Red
Black/Blue 36 11 Blue/Black
Black/Orange 37 12 Orange/Black
Black/Green 38 13 Green/Black
Black/Brown 39 14 Brown/Black
Black/Slate 40 15 Slate/Black
Yellow/Blue 41 16 Blue/Yellow
Yellow/Orange 42 17 Orange/Yellow
Yellow/Green 43 18 Green/Yellow
Yellow/Brown 44 19 Brown/Yellow
Yellow/Slate 45 20 Slate/Yellow
Violet/Blue 46 21 Blue/Violet
Violet/Orange 47 22 Orange/Violet
Violet/Green 48 23 Green/Violet
Violet/Brown 49 24 Brown/Violet
Violet/Slate 50 25 Slate/Violet

Registered Jack (RJ) 48 48X

Pin Pair Signal Color
1 R RX Ring Orange/White
2 T RX Tip White/Orange
3 reserved White/Green
4 R1 TX Ring Blue/White
5 T1 TX Tip White/Blue
6 reserved Green/White
7 shield White/Brown
8 shield Brown/White

T-1 (DS-1, DSX-1) cross over cable

Two pairs crossed, two pairs uncrossed
T1 crossover
Pin Connection 1: T568A
Connection 2: T568B
Pins on plug face
pair color pair color
1 2 Pair 2 Tip
white/orange stripe
1 Pair 1 Ring
blue solid
2 2 Pair 2 Ring
orange solid
1 Pair 1 Tip
white/blue stripe
3 3 Pair 3 Tip
white/green stripe
3 Pair 3 Tip
white/green stripe
4 1 Pair 1 Ring
blue solid
2 Pair 2 Tip
white/orange stripe
5 1 Pair 1 Tip
white/blue stripe
2 Pair 2 Ring
orange solid
6 3 Pair 3 Ring
green solid
3 Pair 3 Ring
green solid
7 4 Pair 4 Tip
white/brown stripe
4 Pair 4 Tip
white/brown stripe
8 4 Pair 4 Ring
brown solid
4 Pair 4 Ring
brown solid

Standard 25 pair wire color code

25 Pair Color Code Chart


Commonly used RS-232 signals and pin assignments

Signal Origin D-subminiature DB-25 D-subminiature DE-9
(TIA-574)
Modified Modular Jack|MMJ Modular connector 8P8C ("RJ45") Modular connector 10P10C ("RJ50")
Name Abbreviation DTE DCE TIA-561 Yost Cyclades National Instruments Cyclades Digi
Transmitted Data TxD 2 3 2 6 3 3 8 4 5
Received Data RxD 3 2 5 5 6 6 9 7 6
Data Terminal Ready DTR 20 4 1 3 2 2 7 3 9
Carrier Detect DCD 8 1 2 7 7 10 8 10 (alt 2)
Data Set Ready DSR 6 6 6 1 8 5 9 2 (alt 10)
Ring Indicator RI 22 9 2 10 1
Request To Send RTS 4 7 8 1 1 4 2 3
Clear To Send CTS 5 8 7 8 5 3 6 8
Common Ground G common 7 5 3,4 4 4,5 4 6 5 7
Protective Ground PG common 1 1 4


Null modem cables and diagrams

DB-25 null modem wiring diagram DE-9 null modem wiring diagram

Signal Name and Abbreviation DB-25 Pin DE-9 Pin Direction DE-9 Pin DB-25 Pin Signal Name Abbreviation
Frame Ground (chassis) FG 1 1 FG
Transmitted Data (TD) TxD 2 3 2 3 RxD
Received Data (RD) RxD 3 2 3 2 TxD
RS-232 Request to Send RTS 4 7 8 5 CTS
RS-232 Clear To Send CTS 5 8 7 4 RTS
Signal Ground SG 7 5 5 7 SG
Data Set Ready DSR 6 6 4 20 DTR
Data Carrier Detect (CD) DCD 8 1
Data Terminal Ready DTR 20 4 1 8 DCD
6 6 DSR



USB connectors and pinouts


File:USB 3.0 Micro B plug.PNG
Micro-B USB 3.0 compatible (cable/male end)
USB 2.0 connector on the side of the specification standard micro USB 3.0 connector are aligned pin-minute increase in the standard.
No.1: power (VBUS)
No.2: USB 2.0 differential pair (D−)
No.3: USB 2.0 differential pair (D )
No.4: USB OTG ID for identifying lines
No.5: GND
No.6: USB 3.0 signal transmission line (−)
No.7: USB 3.0 signal transmission line ( )
No.8: GND
No.9: USB 3.0 signal receiving line (−)
No.10: USB 3.0 signal receiving line ( )
USB 1.x/2.0 standard pinout
Pin Name Cable color Description
1 VBUS Red (Orange*) 5 V
2 D− White (Gold*) Data −
3 D Green Data
4 GND Black (Blue*) Ground
  • * Some manufacturers use
USB 1.x/2.0 Mini/Micro pinout
Pin Name Cable color Description
1 VBUS Red 5 V
2 D− White Data −
3 D Green Data
4 ID None Permits distinction of host connection from slave connection
* host: connected to Signal ground
* slave: not connected
5 GND Black Signal ground

Parallel Printer Pinout