View Full Version : Caused some IEE1394 card damaged

November 15, 2007, 17:32:16
Dear Sir,

We have brought many DMM 31BF03 cams and connecting them to computers in pair via two IEE1394 cards. We have set up around 10 sets of this configurations (1 computer + 2X 1394 cards + 2X DMM 31BF03 cams). Howere we have faced serious problems. Several sets of them have the problem that the 1394 port cards damaged. Since each 1394 cards have 3 sockets, we connect the cam to another socket and it worked again. After some days, the socket died too. And we have damaged around 10 sets 1394 cards.

We have tried to find out what is the problem. Our conclusion is that the power drawn from the computer via the 1394 card to the cam created the problem. The simpliest solution for us is to use external power to supply power to the cams and the 1394 card will not have the power surge problem which lead to the socket damage, we beileved. We doing this by creating tailor made 1394 cables that the power line is re-direct to an external 12V power supply. But when we connect it again, the signal is unstable and we saw the image is flicking.

Could you advise how we can use external 12V power supply (not from computer) to supply power to the cams ? How can we made the custom-made cable for this connection ?

We urgently need the answer and your fast reply will be much appreciated.

Thanks and regards,


Stefan Geissler
November 16, 2007, 08:49:08
Hello K.C.

The documented behaviour is very strange. It would be a great help for me, if you could tell me, what FireWire board you use and what FireWire chip is on board.

You may reduce your problem, if you would use a FireWire hub. In common these hubs have also a power supply plugin.

If the signal seems to be unstable, then you may have the problem with power management of Intel Duo Core CPUs on Laptops. In Windows XP they can be fixed using the "FireWirePerformanceManager" (http://www.imagingcontrol.com/downloads/tools/).

November 16, 2007, 15:32:14
Dear Stefan,

Thanks for your quick reply. To solved this problem, we have brought several type of 1394 cards with NEC, and Texas chips. The problem should not be relating to the brand of cards or chips as we have alrady tested all the cards available in the market after some sockets in the card died.

We used the GP out of cam A to trigger two cam to ensure syn capture of two cams. We used the GP out of cam B to fire a realy which is used to turn on other device. This connection is OK after our testing but just not long lasting. We think may be this connection consumed too many power that caused the 1394 card damaged.

We do not prefer to use a hub as the cams is put in a distance of 2m from the computer and the cables are quite long. Otherwise it will have weak signal problem. Thus we prefer to have custom made cable with external 12V power supply.

Could you advise how to connect the 6-pin cable with the external power supply to the cam ? We tried to just cut the power and GND lines of the cable and connect them to a power supply. But the cam can not be detected by the driver.

Best rgds,