Correction amp to DMX ilda input help please

[DPSS]

Hi everyone,

I've just tried to connect my USB DAC to the ilda input on the DMX board that came with my Scanpro20 scaners and I can't really get it to do anything. I tried playing a wav file generated with Laserboy but nothing. The only thing it displays as soon as I connect the ilda input to the DMX board is this:




I've connected the output pins on the correction amp to the ilda conector as follows:

C.AMP. 1 -> ILDA 1
C.AMP. 2 -> ILDA 14
C.AMP. 3 -> ILDA 2
C.AMP. 4 -> ILDA 15
C.AMP. 11 -> ILDA 6
C.AMP. 12 -> ILDA 19

I've shorted ilda pins 4 & 17 and hooked up pin 13 to the 5v pin from the usb conection on the soundcard.

What am I doing wrong?

[DPSS]

Ok so, after playing arround for a while with the pots on the correction amp and connecting the blanking from the DMX board to the laser, I managed to get the scanners to display the test patterns in Spaghetti not too badly. Here are some pics:







These have been achieved with the blanking signal from the DMX board connected to the laser. For some reason I don't understand, connecting the blanking doesn't eliminate the retrace lines and when I disconnect it, all the patterns jump farther up and right and look more messed up, like this:









Any clues as to what could be the cause?

[keeperx]

i do not use the silly board... just connect directly to the scanners/lasers
if you need help doing it that way let me know we can have some phone tech support time

[heroic]

Any clues as to what could be the cause?

I think your ground/return is floating.

[djscsi]

did you switch the wiring on the cables that go from the program board to the galvo drivers? 2 pins need to be switched - it's in the instruction manual for the program board. just making sure you did this.

otherwise, yes, I would say it's a grounding problem. you can try connecting the ground pins for various components on the board together and see if that affects the output.

[DPSS]

i do not use the silly board... just connect directly to the scanners/lasers
if you need help doing it that way let me know we can have some phone tech support time

Thanks for the phone support offer, but I think phoning to/from Spain mite prove a little expensive.

I had no idea you could connect it all directly, how would it be done?, I mean, the cables sending the signal to the scanner amps have 3 cables for each scanner, but there are only 2 for each channel on the ilda signal.

I think your ground/return is floating.

did you switch the wiring on the cables that go from the program board to the galvo drivers? 2 pins need to be switched - it's in the instruction manual for the program board. just making sure you did this.

otherwise, yes, I would say it's a grounding problem. you can try connecting the ground pins for various components on the board together and see if that affects the output.

I've checked the ilda conector's ground pins being used and they are already connected to eachother thru the correction amp so there is no way of seperating them in the first place. That would be ilda ground pins 14(X),15(Y),18(R),19(G),20(B) and 25 (GND).
Is that what you're both talking about or am I way off?

Domingo.

[heroic]

I've checked the ilda conector's ground pins being used and they are already connected to eachother thru the correction amp so there is no way of seperating them in the first place. That would be ilda ground pins 14(X),15(Y),18(R),19(G),20(B) and 25 (GND).
Is that what you're both talking about or am I way off?

Check between the correction amp and the sound card. I suspect you may have something not quite right in that part of the chain.

[DPSS]

Check between the correction amp and the sound card. I suspect you may have something not quite right in that part of the chain.

The correction amp's inputs are conected to the following on the soundcard:

Pin 1 (G) -> USB Ground
Pin 2 (5v) -> USB 5V
Pin 3 (G) -> Not connected (is connected to ground thru pin 1)
Pin 4 (1) -> Capacitor nº 10
Pin 5 (2) -> Capacitor nº 9
Pin 6 (3) -> Capacitor nº 2
Pin 7 (4) -> Capacitor nº 1
Pin 8 (5) -> Capacitor nº 12
Pin 9 (6) -> Capacitor nº 11
Pin 10 (G) -> Capacitor nº 17

All the connections to the capacitors are done on the chip side.

Domingo.

Edit: I forgot to say the layout of my soundcard is a little diferent than the one seen on the fotos in the forum. Here are some pics so you can see:

[djscsi]

I had no idea you could connect it all directly, how would it be done?, I mean, the cables sending the signal to the scanner amps have 3 cables for each scanner, but there are only 2 for each channel on the ilda signal.

The connectors on the amps allow for a differential input (3-wire) but will accept and work fine with a single-ended input (2-wire). The correction board has single-ended outputs anyway. From the correction board, Pins 1/2 go to the X amp, Pins 3/4 go to the Y amp, and the laser outputs go to the lasers. These are the only connections required. I did this because I could not get the program board to work, and also it seemed unnecessary to wire up the ILDA connectors when just a few pins are necessary to operate the galvos from the USB DAC. Plus I already have nice .1 pin headers on the correction board and my laser drivers, and I like using those to connect things anyway. I would test your connection like this to see if the problem is with the program board or somewhere else. You can use the spare ends of the 3-pin cables which you cut off when making the power supply cables for the amps.

Oh yeah, did you make sure your laserboy WAVs are inverted? If not, its possible that the laser outputs are inverted and causing the weird ground issues (not sure about this though). Try connecting the USB ground to the scanner PSU ground, and also to the laser driver ground if that is coming off a different power supply (mine is). The idea is to make sure that all components are sharing a common ground point. As for the program board->galvo amp wires, you do need to switch 2 pins on one side otherwise the board will not operate the scanners properly. See the program board instructions if you have not done this already, as this could be the problem.

[DPSS]

The connectors on the amps allow for a differential input (3-wire) but will accept and work fine with a single-ended input (2-wire). The correction board has single-ended outputs anyway. From the correction board, Pins 1/2 go to the X amp, Pins 3/4 go to the Y amp, and the laser outputs go to the lasers. These are the only connections required. I did this because I could not get the program board to work, and also it seemed unnecessary to wire up the ILDA connectors when just a few pins are necessary to operate the galvos from the USB DAC. Plus I already have nice .1 pin headers on the correction board and my laser drivers, and I like using those to connect things anyway. I would test your connection like this to see if the problem is with the program board or somewhere else. You can use the spare ends of the 3-pin cables which you cut off when making the power supply cables for the amps.

Oh yeah, did you make sure your laserboy WAVs are inverted? If not, its possible that the laser outputs are inverted and causing the weird ground issues (not sure about this though). Try connecting the USB ground to the scanner PSU ground, and also to the laser driver ground if that is coming off a different power supply (mine is). The idea is to make sure that all components are sharing a common ground point. As for the program board->galvo amp wires, you do need to switch 2 pins on one side otherwise the board will not operate the scanners properly. See the program board instructions if you have not done this already, as this could be the problem.

You're right, I'd forgotten the DMX board had single-ended outputs . I'll try connecting it all directly when I get home tonight and see if the problem still persists.

I'm not using Laserboy for the moment, all my tests are being done with the test patterns in Spaghetti, so I don't think the inverted wav's should be an issue. I'll try joining all the grounds.

About the program board->galvo amp wires, yes, I read the manual and switched the wires the first time I set the scanners up, but thanks for pointing it out.

I'll post my results tonight.

Domingo.