Had a problem with the automatic switching between a Panasonic DVD player and a locally made Ferguson LED TV set. One strange feature of the DVD player is the red standby light comes on when the unit is switched on. Would have thought it would be the other way round, red light is standby. Anyway, everything was sorted out in the end. This got me thinking a about something I read in the EBU Review sometime in the nineties. A proposal to use the SCART connector switching pin 8 to pass control data between devices. No idea if a standard was created for such a system. Many will remember the 1990s was the decade when all sorts of ideas were abound to improve the PAL system such as PAL Plus and the MAC system for satellite transmission. In 1998 terrestrial digital TV saw off all those ideas to improve analogue TV.
Till Eulenspiegel.
Hi Till,
originally pins 10, 12 and 14 of the SCART were earmarked for inter-device communication (balanced pair plus screen, think RS-485 or these days, USB) but I don't think any standard was reached: there was a late modification to pin 8 that allowed for widescreen switching depending upon the voltage present upon said pin.
Not everybody adhered to the standard either: my Panasonic Prism A1 didn't implement source switching on pin 8, presumably because it had several baseband inputs. My mother's Salora however, did.
I had a huge problem with a 00s Alba 14" TV (actually a rebadged Samtel) that whenever I attached a games console via Scart it would go into 16:9 mode with no way of changing it unless there was 12 volts on pin 8, which is a bit of a problem given that most games consoles didn't even have that to output.
I ended up with a separate feed from a mains to 12 volt power supply.
As well as automatically switching the aspect ratio between 4:3 and widescreen, there are some other examples of data over SCART that I've come across.
I recall a Thomson CRT TV and Philips DVD recorder connected by SCART could communicate with each other. It was possible to press a button on the Thomson TV remote to instantly record what you were watching. The recorder would switch on, change to the channel you were watching then start recording. This feature had to be enabled in the recorder's menu before use. I think it was possible to set a timer recording on the DVD recorder via the TV as well, either by selecting the programme from the teletext TV guide or manually. I can't exactly remember now, it was about 20 years ago.
Some Vestel Freeview boxes used some of the pins on their VCR SCART socket as a serial port. I made up a SCART to RS232 cable (still have it!) and used it to update the software on an Alba and Bush Freeview box by connecting it to a PC with the homemade SCART to RS232 cable.
Some (analogue?) satellite receivers could be connected together with a SCART cable, then the tuning settings could be transferred from one receiver to the other (both the same model). This was useful for installers.
HDMI eventually killed off SCART. HDMI became a global standard whereas SCART was Europe-centric - the Americans didn't adopt it. Hardly any new TVs have SCART or analogue inputs these days.
The SCART switching facility was a most useful feature in the Ferguson/Thompson TV sets such as the ICC7 and ICC9 models. The TV set could be switched on from standby by turning on an external device such as a Freeview Box, VCR or DVD player. The TV set would remain switched on while the external device was turned on. Turn off the external device and the TV set would return to the standby state. So how was the switch-over accomplished? Was it the steady state voltage on pin 8 on the SCART connector, or, was the transition from low to high detected to implement the ON function? Conversely, the high to low transition performed the TV receiver OFF function.
Till Eulenspiegel.
@till I suspect a quick look at the manual would reveal all. I seem to recall Panasonic doing some sort of link thing, or am I imagining it?
