ILDA over UTP cable ?

[hobbybob]

@Dixiscan: I just thought i use this DAC with my cheap galvo's for my green single color beamshow laser. (Since the cheap galvo's have the bigger mirrors).
And then use the Easylase with the faster scanners for the future RGB.

I hoped i could use both DACs at the same time with Mamba. (BTW ordered 2.0 today, with a remark they send it quick since i want to use it a UKLEM hahahaa).
Chose web update since i can't risk they send it out too late ';-)
I read it would be possible to connect multiple DAC's (can that also be Easylase and Norms Framestreamer together ?) well... we see... first i need more capacitors since i am a few short.... And i need 3 more balanced output drivers..... probably...

[allthatwhichis]

What is the actual goal here? To avoid buying a 100 foot ILDA cable? To add an additional way to control the projector? To go from USB to something that has a longer "cable" length?

[hobbybob]

The latter.... being able to control a projector from a longer distance.
And being able to just use CAT 5(e) cable to connect everything.

[Stuka]

Hey Stuka,
Did you ever run the FB3 successfully (scanner and all)? I could not tell from the thread whether or not that happened.
How about this for a $100 option: Buy an old used laptop, then network it to your "actual" laptop- use a wireless router if you want. The cheapie laptop would have the usb device connected locally. Use "Remote Desktop" to run/control your software. Not so elegant, but it might do in an emergency. Speaking of emergency though, it does not provide direct access to software shutoff, so you would need to cover that base with your hardwired e-stops etc.
Thanks, Mike

I never did use the USB extension with an actual projector - once I got my QM.net, the FB3 went on the shelf. However, after seeing and hearing about upcoming Pangolin offerings at SELEM, I have a renewed interest in bringing the FB3 back to life!! I also brought an old laptop back to life, so I've been thinking about the Remote Desktop option as well.

Stand by for future developments...

[weartronics]

You know, because of the differential nature of ILDA signals, it is appropriate to use unshielded twisted pair cables instead of D-25 cables. You can use ordinary CAT-5 flexible network cables, and buy D-25 to RJ-45 adapters at each end for $1.50 (e.g. http://www.pccables.com/01915.htm, http://www.pccables.com/01916.htm). You can also use the common type of RJ-45 joiners along the cable without any problem.

The advantage of this technique is that CAT-5 network cable is lighter and more flexible than D-25 cable, it's also cheaper and easier to buy in long lengths. In typical circumstances, signal degradation should be unnoticable over a 500ft cable. With good quality line drivers and receivers, much longer lengths are possible.

One important point of this technique is that you must use ILDA-compliant DACs (which produce differential signals), and amplifiers which sample the differential signals. Also, remember that the +/- components of each signal must use the same twisted pair. Some cheaper DACs only produce single-ended signals, and some cheaper amplifiers only sample single-ended signals. If you use either of these, you must put the DAC quite close to the projector because there is no way to use long ILDA cables without signal degradation. You will even notice it using high quality and shielded D-25 cables.

CAT-5 network cable is ideal for single colour projectors, because there are four pairs which can be used for X, Y, blanking/intensity, and ILDA interlock. If you have an RGB projector, you need to use another type of cable which has more pairs, or use two CAT-5 network cables in parallel.

Best regards,

weartronics

[hobbybob]

I already bought the D-25 to RJ convertors, just didn't have time to test them out.
Will take them to UKLEM, to see it it's working.
Thanks for the ideas Weartronics !

[mikkojay]

The twisted pair & cable type info is very useful- I am surprised I have not seen this discussed in further detail before. Thanks for the info!
-Mike