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What ever happened to SUPERSPEED ?


ItsMeBobO

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three networks 100ft cables on each network with 4 ccrs in series on each network

So you have 100ft out to the first CCR in each network and then a short daisy chain across the 4 CCRs? That doesn't sound like a cable length issue then.

Do you make your own cables? You could try buying a 100' of Cat6 cable and doing a temporary run out to one of the sets of 4 CCRs and see if it works. That's if you have the crimper to make your own cables. Probably a good investment if you are going to be in this hobby.

Finally do you really need the 500K speed...i.e. are you seeing lag issues you are trying to fix or just want the latest version? I just ask because it's more reliable to run the lower speed if you have a lag issue you are trying to fix. Brian was running 6 CCRs per network. I know others have said more than 3 can cause a little lag. I only have 3 on one network along with 2 controllers and 2 CCRs on the other network with 1 controller so I haven't stressed the 115K very much.

Edited by Gilrock
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forddieseldean, you said you redownloded the firmware, but you don't have to, it's included in the 3.9 software. If your downloading firmware version 1.07 from the lightorama web-site, that is NOT the latest firmware. You need to install CCR Firmware version 1.10 using the Hardware utility.

sorry i didn't mean redownloaded i meant reinstalled 1.10
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So you have 100ft out to the first CCR in each network and then a short daisy chain across the 4 CCRs? That doesn't sound like a cable length issue then.

Do you make your own cables? You could try buying a 100' of Cat6 cable and doing a temporary run out to one of the sets of 4 CCRs and see if it works. That's if you have the crimper to make your own cables. Probably a good investment if you are going to be in this hobby.

Finally do you really need the 500K speed...i.e. are you seeing lag issues you are trying to fix or just want the latest version? I just ask because it's more reliable to run the lower speed if you have a lag issue you are trying to fix. Brian was running 6 CCRs per network. I know others have said more than 3 can cause a little lag. I only have 3 on one network along with 2 controllers and 2 CCRs on the other network with 1 controller so I haven't stressed the 115K very much.

i bought these cables and i do have crimpers to do my own.......is cat 6 cable a must i have 5e. it is not lagging i just was trying it out and noticed the missed commands and really smooth Edited by forddieseldean
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I was trying to research the data rate limits for RS-485. I found a nice table where Texas Instruments did testing for RS-232 but not for RS-485. But I did find this bit of information. Most of these factors you will not be able to control except for the length and quality of the cable. Some of the other factors are in Light-o-rama's hands when they design the hardware.

What Factors Limit the RS-485 Data Rate?

The following factors affect how far one can reliably transmit at a given data rate:

  • Cable length: At a given frequency, the signal is attenuated by the cable as a function of length.
  • Cable construction: Cat5 24AWG twisted pair is a very common cable type used for RS-485 systems. Adding shielding to the cable enhances noise immunity, and thereby increases the data rate for a given distance.
  • Cable characteristic impedance: Distributed capacitance and inductance slows edges, reducing noise margin and compromising the 'eye pattern'. Distributed resistance attenuates the signal level directly.
  • Driver output impedance: If too high, this limits drive capability.
  • Receiver input impedance: If too low, this limits the number of receivers that the driver can handle.
  • Termination: A long cable can act like a transmission line. Terminating the cable with its characteristic impedance reduces reflections and increases the achievable data rate.
  • Noise margin: Bigger is better.
  • Slew rate of driver: Slower edges (lower slew rates) enable transmission over longer cable lengths.

Edited by Gilrock
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I do all my own cables and use Cat 5e, havn't had any problems. My longest run is 175 feet, all together I'm running about 700ft. The two cables (2-networks) running to my CCR tree (12-ribbon) is only about 60 feet each.

Edited by Frank Farmer
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I was trying to research the data rate limits for RS-485. I found a nice table where Texas Instruments did testing for RS-232 but not for RS-485. But I did find this bit of information. Most of these factors you will not be able to control except for the length and quality of the cable. Some of the other factors are in Light-o-rama's hands when they design the hardware.

What Factors Limit the RS-485 Data Rate?

The following factors affect how far one can reliably transmit at a given data rate:

  • Cable length: At a given frequency, the signal is attenuated by the cable as a function of length.
  • Cable construction: Cat5 24AWG twisted pair is a very common cable type used for RS-485 systems. Adding shielding to the cable enhances noise immunity, and thereby increases the data rate for a given distance.
  • Cable characteristic impedance: Distributed capacitance and inductance slows edges, reducing noise margin and compromising the 'eye pattern'. Distributed resistance attenuates the signal level directly.
  • Driver output impedance: If too high, this limits drive capability.
  • Receiver input impedance: If too low, this limits the number of receivers that the driver can handle.
  • Termination: A long cable can act like a transmission line. Terminating the cable with its characteristic impedance reduces reflections and increases the achievable data rate.
  • Noise margin: Bigger is better.
  • Slew rate of driver: Slower edges (lower slew rates) enable transmission over longer cable lengths.

my cables are cat 5E twisted pair 24 awg and they are kept far away from electrical lines

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Well I'm just throwing out the possibility of long cables being one source of issues. It sounds like some folks are using the higher speed with no issues and others are having problems so things like bad cable connections or long cable runs are possibilities. I also know they advertise 4000' for RS-485 but I just found another reference that indicates at 4000' the max data rate is about 100 Kb/s. When you increase the rate to 500Kb/s the max cable distance looks like it drops to around 650'.

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  • 9 months later...

Sorry to revisit this subject but......

 

#1 Is there ANY way to know if the RS-485's are 500k compatible ?  I bought them about 14 months ago.

 

#2 I've read conflicting reports that if ALL the controllers on a network are not 500k 'compatible' it will wreak havoc in the signal processing speeds and cause 'issues.'  Anyone verify that ?

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Each network runs independent of the other. If one of your networks had an RS-485 that was not 500K compatible I do not see how it could effect the performance of the other networks.

For me, I have two of the 485's that are rated for 500K and I have some old ones that are not. I tried the 500K rated ones and saw no difference. I am currently using the old ones and am running 500K and everything works fine. My most recent videos are using 500K and the old adapters that are not rated for 500K.

But you might want to go ahead and get the 500K compatible ones, because otherwise every time you have a problem of any type you will wonder if it is being caused by your RS-485 adapters.

By the way, if you did have a problem with an adapter I would expect the signal to be "noisy" and commands would occasionally get sent wrong or commands would be missing resulting in channels that spuriously stay on when they shouldn't or occasionally don't come on at all. But that's just a guess, I have never experienced the problem myself.

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To add to this, after the 500k came out last year, I updated all controllers to the new firmware. 1 controller out of 7 did not work after starting a sequence. The other 6 plus 4 ccp controller s worked just as expected. This was on 485s < 2 years old. There were no issues controllers or sequences with the exception of the lone controller.

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#1 Is there ANY way to know if the RS-485's are 500k compatible ?  I bought them about 14 months ago.

With 100% certainty? No, there is not. The USB485-ISO, however, seems to have a pretty good track record of being able to handle the 500k speeds. You could test by creating a sequence with 12+ CCR's (or even 12+ CCB's) and seeing how they respond. Remember, even if you have only one CCR, a sequence with 12 CCR's in it will still flood the network. Doesn't matter what is connected, the data still goes out.

 

#2 I've read conflicting reports that if ALL the controllers on a network are not 500k 'compatible' it will wreak havoc in the signal processing speeds and cause 'issues.'  Anyone verify that ?

If you have any non-G3 controllers on a network with 500k compatible devices, you will have problems. I've not tested it myself, but I know the people at Light-O-Rama have, and have encountered the error. Any non-500k compatible controller should be on its own network. This includes CCR/P/B controllers that have not been updated with a current revision of firmware.

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