x10 Protocol

X10 communicates between transmitters and receivers by sending and receiving signals over the power line wiring. These signals involve short RF bursts, which represent digital information.

The protocol control some simple actions in house such as: switching on/off the bulbs of the lighting system, switching the household goods, window blinds control, temperature control for heating of cooling systems in house, and so on.

As well as being controlled locally as normal, appliances can also be controlled remotely using keypads, radio and infrared remote controls, timers, and computer interfaces. Using Internet or telephone control allows control from any distance from the house.

X10 principles

X10 works by carrying control signals over the domestic mains power wiring. Because most houses are wired so that all power and lighting circuits originate from the same point, a control device in one part of the house can control appliances in another part. This means that controllers do not have to be wired directly to appliances.

Control signals can be generated by various sources, including plug-in controllers, radio and infrared receivers, and computer interfaces. Appliance and lamp controllers, among other things, detect these signals. T

he X10 protocol also provides for a controller to determine the status (on or off) of an appliance, although many appliance modules don't support this.
Embedded in each X10, signal is a `house code' and a “unit code”. Both of these can take values between 1 and 16.

Table 5.2 Control codes and addressing codes for protocol X10


House Codes

Key Codes (unit code)

H1

H2

H4

H8

D1

D2

D4

D8

D16

A

0

1

1

0

1

0

1

1

0

0

B

1

1

1

0

2

1

1

1

0

0

C

0

0

1

0

3

0

0

1

0

0

D

1

0

1

0

4

1

0

1

0

0

E

0

0

0

1

5

0

0

0

1

0

F

1

0

0

1

6

1

0

0

1

0

G

0

1

0

1

7

0

1

0

1

0

H

1

1

0

1

8

1

1

0

1

0

I

0

1

1

1

9

0

1

1

1

0

J

1

1

1

1

10

1

1

1

1

0

K

0

0

1

1

11

0

0

1

1

0

L

1

0

1

1

12

1

0

1

1

0

M

0

0

0

0

13

0

0

0

0

0

N

1

0

0

0

14

1

0

0

0

0

O

0

1

0

0

15

0

1

0

0

0

P

1

1

0

0

16

1

1

0

0

0

All units OFF

0

0

0

0

1

All lights ON

0

0

0

1

1

ON

0

0

1

0

1

OFF

0

0

1

1

1

Dim

0

1

0

0

1

Bright

0

1

0

1

1

            All Lights Off

0

1

1

0

1

Extended Code

0

1

1

1

1

Hail Request

1

0

0

0

1

Hail Acknowledge

1

0

0

1

1

Pre-set Dim (1)

1

0

1

0

1

Pre-set Dim (2)

1

0

1

1

1

Extended Data Transfer

1

1

0

0

1

Status On

1

1

0

1

1

Status Off

1

1

1

0

1

Status Request 

1

1

1

1

1

Each appliance or lamp is set to respond to a single house code/unit code combination. The house code was originally intended to allow adjacent houses to use X10 without interfering with each other; this is necessary in theory because houses in the same neighbourhood may share a connection to the power distribution system, so that control signals can `bleed' from one to another.

In the UK, where uptake of X10 has not been widespread, the house code and unit code can both be used to select which device to control. This means that a total of 256 devices can be controlled independently in a given property.


PC/talker

Interface/Listener

Header Code (2 bytes):

7

6

5

4

3

2

1

0

Dim Code (0 to 22)

1

F/A

E/S

Address:


7

6

5

4

3

2

1

0

House code

Device code

x10 protocol or functionor

Function:


7

6

5

4

3

2

1

0

House Code

Function Code

x10 protocol transmission

Checksum :
(Header Code + second byte&0xFF)

x10 protocol arrowOK for transmission => 0x00

Interface ready: => 0x55

Figure 5.1 Protocol X10 flow diagram communication (version DBS1.4) 

F/A = 1 the second header byte will be a function code word (see structure); F/A=0 the second header byte will be a address word; E/S=1 the header represents an extended transmission command; E/S=0 the header represents a standard transmission command.

For other specific code please find the significance on site: www.x10.com/support
The data transmission using X10 protocol is synchronized to the zero crossing point of the AC power line. Close from this moment (max. 50 ms delay is accepted) the data transmission should start.

A Binary 1 is represented by a 1 ms burst of 120 kHz at the zero crossing point, and a Binary 0 by the absence of 120 kHz. These 1 ms bursts should equally be transmitted three times to coincide with the zero crossing point of all three phases in a three phase distribution system.          

 
Modulation of signals in X10 protocol
Animation 5.2 Modulation of signals in X10 protocol

A complete code transmission encompasses eleven cycles of the power line. The first two cycles represent a Start Code that together with next four cycles house code forms the header of transmission.  These considerations are available for the patented X-10 protocol and the two-way line driver TW523 module (O.E.M.). For more information please read the technical note The X-10 Powerhouse Two ways Power Line Interface TW523, revision 2.4b Dave Rye.

X10 two-way driver TW523

Figure 5.2 X10 two-way driver TW523

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