System and method for communicating data in a video system
View Patent ↗A system and method of controlling a video camera arranged to provide a video signal on a transmission medium including: transmitting command data on the video transmission medium to the camera, and receiving response data from the camera over the video transmission medium during a single vertical blanking period of the video signal, improving controllability of dome type cameras. Using an encoding format with data with bit widths narrower than those conventionally used in UTC protocols, increases the usable transmission medium length for the system by allowing for longer propagation delays without errors caused by interference. A method of downloading data to a camera by disabling the video signal, and a method of self-instantiating camera functions are also provided.
1. A method of controlling a controllable video device configured to provide a video signal on a transmission medium, the method comprising:
transmitting command data to the controllable video device over the transmission medium in a vertical blanking period of the video signal;
receiving said command data at the controllable video device; and
transmitting response data using the controllable video device over the transmission medium during the same vertical blanking period in response to said command data; wherein the command data and response data each comprise a plurality of bits encoded in a format wherein a first logic value is represented by presence of a transition during a bit period and a second logic value is represented by absence of a transition during said bit period, and said command data and said response data each comprise 8 bytes of data, and said command data is transmitted in four separate 2 byte portions, with each of said separate two byte portions being transmitted on one horizontal line in a first group of four associated consecutive horizontal lines in said vertical blanking period, and said response data is transmitted in four separate 2 byte portions, with each of said separate two byte portions being transmitted on one horizontal line in a second group of four associated consecutive horizontal lines in said vertical blanking period.
2. A method according to claim 1 , wherein said command data is configured to cause adjustment of a plurality of operating characteristics of the controllable video device.
3. A method according to claim 1 , wherein the controllable video device is a dome-type camera and wherein said command data is configured to cause control of all axes of movement for said camera.
4. A method according to claim 1 , wherein said command data is configured to cause adjustment of at least one operating characteristics of the controllable video device, and wherein said controllable video device is configured to arrest said adjustment of said at least one operating characteristic in response to passage of a predetermined amount of time from receipt of said command data.
5. A method according to claim 1 , wherein said response data is configured to indicate alarm status of the controllable video device.
6. A method according to claim 1 , wherein said first and second groups of consecutive horizontal lines are separated by at least one horizontal line.
7. A method according to claim 1 , wherein the video device is a dome-type video camera and said command data includes data configured to control the zoom, focus, pan and tilt functions of the device.
8. A video system comprising:
a controllable video device configured to transmit a video signal on a transmission medium; and
a command source configured to receive said video signal and to transmit command data to said controllable video device through said transmission medium during a vertical blanking period of said video signal,
said controllable video device being configured to transmit response data to said command source through said transmission medium during said vertical blanking period, said response data being in response to said command data,
wherein the command data and response data each comprise a plurality of bits are encoded in a format wherein a first logic value is represented by presence of a transition during a bit period and a second logic value is represented by absence of a transition during said bit period, and said command data and said response data each comprise 8 bytes of data, and said command data is transmitted in four separate 2 byte portions, with each of said separate two byte portions being transmitted on one horizontal line in a first group of four associated consecutive horizontal lines in said vertical blanking period, and said response data is transmitted in four separate 2 byte portions, with each of said separate two byte portions being transmitted on one horizontal line in a second group of four associated consecutive horizontal lines in said vertical blanking period.
9. A system according to claim 8 , wherein the controllable video device is a dome-type camera and wherein said command data is configured to cause control of a pan condition, a tilt condition, and a zoom condition of said camera.
10. A system according to claim 8 , wherein said command data is configured to cause adjustment of at least one operating characteristics of the controllable video device, and wherein said controllable video device is configured to arrest said adjustment of said at least one operating characteristic in response to passage of a predetermined amount from receipt of said command data.
11. A system according to claim 8 , wherein said response data is configured to indicate alarm status of the controllable video device.
12. A system according to claim 8 , wherein said first and second groups of consecutive horizontal lines are separated by at least one horizontal line.
13. A system according to claim 8 , wherein the video device is a dome-type video camera and said command data includes data configured to control the zoom, focus, pan and tilt functions of the device.
14. A method of controlling a controllable video device configured to provide a video signal on a transmission medium, the method comprising, providing a command source in bi-directional communication with the controllable video device which is operable to control the operation of the video device;
transmitting a function command to said controllable video device over the transmission medium, wherein said function command comprises data transmitted in separate portions, each of said separate portions being transmitted on an associated one of a plurality of horizontal lines in said vertical blanking period, each of said portions comprising a plurality of bits encoded in a bit period, a first logic value of each of said bits being represented by presence of a transition during said bit period and a second logic value of each of said bits being represented by absence of a transition during said bit period;
transmitting reply by said controllable video device data to said command source, said reply data being in response to said function command and being configured to cause display of a plurality of available functions for said controllable video device, wherein said reply data comprises data transmitted in separate portions, each of said separate portions being transmitted on an associated one of a plurality of horizontal lines in said vertical blanking period, each of said separate portions comprising a plurality of bits encoded in a bit period, a first logic value of each of said bits being represented by presence of a transition during said bit period and a second logic value of each of said bits being represented by absence of a transition during said bit period, and;
transmitting a function start command to said controllable video device in response to said reply data, said function start command being configured to cause said controllable video device to perform at least one of said plurality of available functions.
15. A method according to claim 14 , wherein said function command is transmitted to said controllable video device in response to activation of at least one user interface control on said command source.
16. A method according to claim 15 , wherein said user interface control comprises a button on a user interface of said command source.
17. A method according to claim 14 , wherein said reply command is configured to cause the command source to display a numeric value associated with each of said available functions for said controllable video device.
18. A method according to claim 17 , wherein said function start command comprises data representing one of said numeric values associated with said at least one of said plurality of available functions.
19. A method according to claim 14 , wherein at least said function command and said reply data are transmitted during a single vertical blanking period of said video signal.
20. A method according to claim 14 , wherein each of said separate portions comprises 16 bits.
21. A video system comprising:
a controllable video device configured to transmit a video signal on a transmission medium; and
a command source including a user interface control for causing function command data to be transmitted to said controllable video device over the transmission medium, wherein said function command comprises data transmitted in separate portions, each of said separate portions being transmitted on an associated one of a plurality of horizontal lines in said vertical blanking period;
said controllable video device being configured to transmit reply data to said command source in response to said function command, wherein said reply data comprises data transmitted in separate portions, each of said separate portions being transmitted on an associated one of a plurality of horizontal lines in said vertical blanking period, said reply data being configured to cause display of a plurality of available functions for said controllable video device;
wherein said separate portions of said function command data and said reply each comprise a plurality of bits encoded in a bit period, a first logic value of each of said bits being represented by presence of a transition during said bit period and a second logic value of each of said bits being represented by absence of a transition during said bit period.
22. A system according to claim 2 , wherein said command source is configured to transmit a function start command to said controllable video device in response to said reply data, said function start command being configured to cause said controllable video device to perform at least one of said plurality of available functions.
23. A system according to claim 21 , wherein said user interface control comprises a button on a user interface of said command source.
24. A system according to claim 21 , wherein said reply command is configured to cause said command source to display a numeric value associated with each of said available functions for said controllable video device.
25. A system according to claim 21 , wherein said function start command comprises data representing one of said numeric values associated with said at least one of said plurality of available functions.
26. A system according to claim 21 , wherein said command source and said controllable video device are configured to transmit said function command and said reply data, respectively, during a single vertical blanking period of said video signal.