Gento's scanner safety board

[iggythebrush]

Here's a pic of the amps - sorry about the quality, I only have my phone to hand. The amp board is marked tarm SLLT GmbH Cambridge Scan Drv Rev 1.5.

The scanners are CT6800's, I have a 'scope to hand if necessary.

PS I have no manual but there may well be feedback signals available on the scanner board input (9-way).

Thanks

[greenalien]

http://www.cambridgetechnology.com/contact/index.html

[iggythebrush]

Thanks Greenalien, I know the pinouts of the CT scanners - they have the standard position transducer +/- outputs - but presumably these can't be used without lots of buffering (and would possibly have an impact on the accuracy of the scanner)?

[greenalien]

Please don't try to connect anything between the scanners and the amp - those leads are very sensitive, it even matters which make of cable is used, because the signals on the cables are very small. For feedback, you definitely need a properly buffered high-level signal from the amp board - if that has not been included in the board design, then it will need additional circuitry. I suggest you contact Cambridge, with your board details, and ask them about the connection for a feedback signal.

[Doc]

DT40 Pro amps (thanks to DZ for pointing them out )

[mixedgas]

I think you might find the following interesting as a aid to tracing the cloned cambridge amplifiers.

Thats a 6850 series amp, spread out and redone as two amps on a board. At least the ones in TARM.jpg

http://www.skywise711.com/lasers/scanner/scanner.html

Skywise hosts that for me.

Steve

[iggythebrush]

Thanks Mixedgas, position outputs traced and connected - scanner safety working. In fact, the Fiberray amps have a connection prepared for the position outputs, but they are not connected.

[greenalien]

The chance of getting (and posting!) the circuit diagram of a commercial scanner amp is not too great, I assume...

With Mixedgas on board, it's surprising what's possible - Nice one, Steve!!

[dave]

While we're on the subject, this might be a good opportunity to list scan amps that do have a dedicated feedback signal. Here's the ones listed in the scansafe manual:

All the scanners we sell have a position output, or in the case of the scanlsp's I can tell you where to tap it off fro..

[iggythebrush]

Another stupid question:

I am running a QM2000 board with a NEOS PCAOM driver (bipolar inputs). The scanner safety board only has unipolar modulation inputs and outputs. When everything is connected in a bipolar fashion, with the colour minus connections straight through to the PCAOM driver, and the plus going via the scanner safety, the PCAOM works perfectly and I can also see that the scanner safety board is working (LED changes colour), but the laser is not completely shut off when the LED goes red (although it does substantially decrease in intensity).

When connected in a unipolar fashion (colour minus not used, ground reference for colour minus inputs on PCAOM driver) the PCAOM does not appear to work properly (very noisy, lower intensity), although the laser does shut off properly when LED goes red.

Any way round this issue? Am I being stupid here?

Merry Christmas and happy holidays to everyone!

[cyberb0b]

For easy use,

Here are the test frames in an .LDS

[kl79]

thank's !
I haven't power up my board for now...I must do it !

[Gento]

Verbesserte Software.

Gento

Link: http://www.Laser-safety.de/USB_Safety_English.rar

[mccarrot]

Thanks Gento,

I have been playing with the scanfail but even at 1% move and 20mSec its does blank too much.

I have only adjusted it with the USB adjustment tool, I have not used the 3th test frame for finetuning yet.
What is the best way to make the scanfail less sensitve?

[mccarrot]

Thanks Gento,

I have been playing with the scanfail but even at 1% move and 20mSec its does blank too much.

I have only adjusted it with the USB adjustment tool, I have not used the 3th test frame for finetuning yet.
What is the best way to make the scan fail less sensitive?

[blowfly]

Now that you guys have been playing with the Scanfail board for a while, what do you think? Is it worth the price?

I admit that as a noob, i'm a little excited about designing my own safety circuits and stuff. It all looks pretty straightforward and will just take some time to get it right. Getting it wrong would suck though, especially if someone got hurt... so I'm wondering if it's worth shelling out the cash for a Scanfail board.

Mike

[Doc]

Now that you guys have been playing with the Scanfail board for a while, what do you think? Is it worth the price?

I admit that as a noob, i'm a little excited about designing my own safety circuits and stuff. It all looks pretty straightforward and will just take some time to get it right. Getting it wrong would suck though, especially if someone got hurt... so I'm wondering if it's worth shelling out the cash for a Scanfail board.

Mike

The scanfail is good value, definately worth the money.

[blowfly]

Glad to hear it's is as cool as it looks.

Where's the best place to buy a ScanFail kit? The web site for the software doesn't say where one can be purchased.

Mike

[mccarrot]

PM send....

....

[blowfly]

Hi Dave,

Where can you tap the SCAN30LSP to get the position feedback for scanfail detection? You mentioned there is a lead for this a few posts back.

Thanks,
Mike

[dave]

Hey Mike,

Check your PM's regarding position tap off.

Dave

[greenalien]

I finally managed to find the time to finish installing the safety board in my projector, and have succesfully calibrated it, using the USB link and PC software, with test image 3. As it took some time to get the adjustment of the 4 pots correct, it would be good if the PC software test mode had the option to run for more than 60 seconds continually - 5 minutes would be better, especially as there is an option to cancel it at any time.
I then set up the 2 protected zones in the PC software (both the same, for now) to allow 50% coverage, i.e. the top half of the display area is not protected, the bottom half has protection enabled. I made my own test frame with 4 static points, 2 above the 'horizon', 2 below. This works well in 60-second test mode - the 2 upper points are displayed while the 2 lower ones are blanked - but I have been unable to transmit the data permanently to the projector - I get various different cryptic error messages that appear to refer to the screen coordinates, and the message bar turns red.
So far, I've only tried it with DIP switches 4 and 5 ON.
Any suggestions?

[Doc]

I finally managed to find the time to finish installing the safety board in my projector, and have succesfully calibrated it, using the USB link and PC software, with test image 3. As it took some time to get the adjustment of the 4 pots correct, it would be good if the PC software test mode had the option to run for more than 60 seconds continually - 5 minutes would be better, especially as there is an option to cancel it at any time.
I then set up the 2 protected zones in the PC software (both the same, for now) to allow 50% coverage, i.e. the top half of the display area is not protected, the bottom half has protection enabled. I made my own test frame with 4 static points, 2 above the 'horizon', 2 below. This works well in 60-second test mode - the 2 upper points are displayed while the 2 lower ones are blanked - but I have been unable to transmit the data permanently to the projector - I get various different cryptic error messages that appear to refer to the screen coordinates, and the message bar turns red.
So far, I've only tried it with DIP switches 4 and 5 ON.
Any suggestions?

I was getting errors 90% of the time when using my desktop (XP Pro, SP3), but works every time from my laptop (also XP Pro SP3).

Computers are the Devil's work.

[mccarrot]

Try to first Upload from the scanfail, then change the zones and the send it back.

[greenalien]

Cheers McCarrot, that seems to have done the trick - still took a few goes, but I finally got the green bar!
My DIP switches are now DIP 1,2, 5 - on; dip3,4 - off.
If I try to display a frame with a single beam 'below the horizon' it's instantly cut off, whereas a frame with a single beam 'above the horizon' lets the beam through - and it still remembers the settings, even after switching the projector off and on again. Great!!!

One more query - what should be connected to JP3 pins 1 / 2 - it says 'blank input' but I'm unsure where this should come from - the manual doesn't give any details. I'm guessing that it could be ILDA pins 3 and 16, also called Intensity - or should it be Shutter pin 13 / ground, pin 25? Anyhow, it doesn't seem to be needed as the scanfail seems to be working without anything connected to it - or am I missing something?