FB3 hookup - help!!!

[JimBo]

Check your wires, it looks like one is disconnected/broken.

Jim

[buffo]

Randy;

If you scanners are screaming, squealing, buzzing, or whining, that's usually a sign that they're being overdriven. A little bit of noise once in a while is OK, but if they are constantly making these sounds, and *especially* if hearing the sound makes you wonder if you are overdriving them, then rest assured that YOU ARE OVERDRIVING THEM.

Double-check everything and then post back here with your results.

Adam

[mliptack]

I hate that statement - no offense Adam but my DT40 Pros even operating at ILDA specs squeal quite a bit more than I expected - and still do. I was terrified when I first got them because everyone said they **shouldn't** make much noise at all. Well for me almost ANY pattern displayed will produce enough noise to hear it over my laptop speakers. Maybe I'll borrow a dB meter from work - or buy a nice one just to get a good idea of the amount of noise I am getting. That would have to do for the time being until I meet a fellow PhotonLexiconer who has been around the block a few times. Well either way - I don't think mine are being over driven and they have plenty of usage on them :P

-Max

[Stuka]

Here's an interesting twist, thanks to a tip I received in e-mail from Barry ("dazebtwn" here on the forums) -

It appears that the documentation that came with my FB3 depicts the FB3 motherboard to DMX daughterboard connection, NOT the DB25 projector connections, which do appear to conform to the ILDA standard.
It's a little misleading the way it's depicted in the documentation - at least for us noobs!!

Per Barry's tip, (and follow up from tocket - thanks guys!!) I followed the ILDA pinout (at least for the X+ and Y+ amp connections), and I now appear to have a working set of scanners! I still have some testing and fine-tuning to do with the remaining connections from the FB3, but it looks like I'm heading in the right direction.
Sweet - scanners working, and nothing melted!!

More to follow as things progress.....

[tocket]

Oh, the pinout in the FB3 manual is not for the DB25 female. That one has the standard ILDA pinout. The pinout is for that red internal connector on the board. Looking at the flat cable between the two it is fairly evident that the pinouts are different.

It is interesting what you did though, as you had connected X+ correctly (pin 1 in both configurations), but Y+ of the amp was wired to Intensity signal of the FB3 and Y- to Interlock A. This still produced a vertical line with laser output off, which indicates that interlock A is not a fixed voltage. I did not know this!

I'm certain things will go much better now that you know what's wrong and how to fix it. Looking forward to seeing the results and I hope your scanners did not take any damage from this.

[buffo]

Tocket;

Interlock A should have been unconnected. The interlock pins simply make a loop between A and B inside the controller. They're not connected to anything else, and the controller doesn't put any voltage on those pins. At best, it would have been floating at whatever potential the scanner amp Y - pin was at.

My guess is that he was getting the Y axis to move based on the variable signal on the positive intensity signal line. I don't think the interlock line had anything to do with it.

Still, good call on figuring out that he was using the pinout for the daughterboard connector and not the ILDA port!

Max:

I think you have very sensitive ears! I listened to the recording you made of you playing guitar, and I couldn't hear any of the noise sources you complained about. So maybe to you, it does sound like your scanners are screaming.

They always make a little noise when operating, but usually that noise can't be heard over the sound of the projector case fans. (Then too, the projector case itself serves to muffle any sounds coming from within.)

I will admit that of all the scanners I've tested, the DT-40's (and even the newer DT-40 pro's) seem to be the loudest. They make more noise than any other scanner I've ever worked with. But when you start pushing them, they *really* get loud! That's when you're in the danger zone. (Fortunately, most of the time the poly switch will trip and save your ass.)

It may be that you are so used to looking for abnormal sounds that you can hear the scanners even when they're operating normally, and even when the fans on the projector are trying to drown the sound out. You are also younger, so your hearing is likely to be much more accute than mine. Given all the above, I'd have to say that your scanners are probably just fine - even if they do sound noisy to you.

But when an old fart like me can still hear the scanners squealing, then something is wrong! Randy has heard my projector when it's running, and it doesn't sqeal, so based on that (plus what we now know about the wiring mixup he had), I'd say that his scanners probably *were* making some unnatural sounds...

Adam

[Stuka]

Hey, I'm part of that "old fart" group, and after 20+ years of exposure to turbine engine noise, I was definitely concerned about the sounds coming from my scanners!! They weren't just "unnatural" sounding - it was downright scary!!!

Thankfully, all ends well -
I was made aware of my noob misinterpretation errors, and I'm happy to say I successfully generated all the images that came with LiveQUICK and LivePRO - at least with single-color, non-blanking lasers (that part isn't hooked up yet!!) And best I can tell, nothing was melted, fried, or otherwise damaged beyond repair in my futile, error-filled initial attempts at hooking up my scanners!!

Thanks to everyone who chimed in and guided me in the right direction

Randy

[tocket]

Good to hear that your scanners are working fine! I hate killing expensive stuff because of stupid mistakes (and it happens to me a lot).

Interlock A should have been unconnected. The interlock pins simply make a loop between A and B inside the controller. They're not connected to anything else, and the controller doesn't put any voltage on those pins. At best, it would have been floating at whatever potential the scanner amp Y - pin was at.

Ah... yes, the interlock test circuit is of course on the projector side of things. Since Interlock B is on pin 17 it was probably left floating. The intensity pin should have been at a fixed voltage since laser output was off (the last picture).

I know that op-amps can do strange things when you leave one of their input pins floating, but I wouldn't have expected anything like that.

[mliptack]

I think you have very sensitive ears! I listened to the recording you made of you playing guitar, and I couldn't hear any of the noise sources you complained about. So maybe to you, it does sound like your scanners are screaming.

They always make a little noise when operating, but usually that noise can't be heard over the sound of the projector case fans. (Then too, the projector case itself serves to muffle any sounds coming from within.)

I will admit that of all the scanners I've tested, the DT-40's (and even the newer DT-40 pro's) seem to be the loudest. They make more noise than any other scanner I've ever worked with. But when you start pushing them, they *really* get loud! That's when you're in the danger zone. (Fortunately, most of the time the poly switch will trip and save your ass.)

It may be that you are so used to looking for abnormal sounds that you can hear the scanners even when they're operating normally, and even when the fans on the projector are trying to drown the sound out. You are also younger, so your hearing is likely to be much more accute than mine. Given all the above, I'd have to say that your scanners are probably just fine - even if they do sound noisy to you.

But when an old fart like me can still hear the scanners squealing, then something is wrong! Randy has heard my projector when it's running, and it doesn't sqeal, so based on that (plus what we now know about the wiring mixup he had), I'd say that his scanners probably *were* making some unnatural sounds...

Adam

Yeah, I agree, you are probably right. This is of course one of the reasons I almost ALWAYS wear earplugs at shows. Some of the shows I have seen lately are at scary volumes - of course the ear can recover to a degree, but I enjoy my hearing.

I just have a hard time trying to quantify the term 'squealing' in a text based forum. Maybe I will use the same recording setup to record the noise from the DT40 Pros. I just wont use any noise canceling on that track

Like I said regarding the guitar playing I am my worst critic, I spent a good hour or so eliminating all the noise out of the setup before I even put a CD in the drive.

-Max

[Lasershow]

Hi guys,
But I do want to correct one thing, and it is something that is really subtle and easy to overlook. You should NOT!!! connect the "ground" of the DB25 ILDA signal to the "ground" of scanner amps!! In fact, you should not connect anything at all to the "ground" of a scanner amp (except for the "common" wire of the power supply).

With all due respect for the your knowledge Bill, but I think you should not generalize and to affirm that "NOT Should connect the "ground" the DB25 ILDA signal to the "ground" of scanner amps" for any signal connections, because each wiring is a situation specifies, due to the scanner type, amps, power supply etc... contained in the projector and therefore, I suggest to connect the amps ground, testing and verifying the performance of the projections in several conditions and in agreement with the results, to connect or not, reminding that Cambridge Technology, world leader in the production of scanners and servo drivers, recommends to connect the ground for Analog Differential Input Configuration, according to passage (below) of the manual of Micromax 671 Series, pag.46
"There should be the direct ground connection from the signal source to the Pin 2 on the input connector (J1, Pin2 - ground) on the shield of the wire or the separate wire. If shield wire is not available, use a third wire then twist all wires to provide some level of shielding", still recommending to connect wire between both grounds on specific points of the servo drivers (Dual Axis System), to avoid strong coupling between channels, reducing crostalk between the two channels caused by high ground currents.

Best Regards

Carlos