Hello AllWhat is the maximum amount of loconet devices that can be connected beforehaving to add an LNRP?We currently have about 25 DS64/54's 7 DB150;s 3 BDL168's, 2 PM42's, 3 UR91's, 1UR92,and 3 Computer connection. When throttles are used during ops sessions theyusually have batteries in them but on occassion I think the voltage gets a bitlow on the loconet if a throttle is plugged in withtout a battery.
We have 2 LNRP's and are waiting for 4 more to come in before installing. Thinking about doing an partial install before the end of month ops session.
Springfield PA
If you power things properly, ie use power supplies for UR91's and UR92's, and UP5's so the throttles don;t kill the Loconet, you'll run out of bandwidth before you have to many devices connected. The LNRP doesn;t really increase the number of devices you can attach, what it does is isolate segmetns of teh network so a problem on one side, like a bent pin in a UP5 that shorts out when you plug in a throttle, doesn't shut down the entire network. In network temrinology it's more of a bridge than a switch, in that it rgenerates packets but it does not do any selective routing.
Only issue you mentioned is low boltage - power all the UP5's. Do NOT use the solder hole in the back to transmit power from one to the other, that's just the positive terminal, the ground is still in Loconet when you do that. Radio Shack has the proper size coax plugs, so you cna use a single say 1 amp power supply of 14-15VDC and run two wires to each UP5 and tap off to one of those coax conenctors and plug it in. Beats having a dozen PS14's.You cna apply power to any UR91s and UR92s this samew way, they can share a common power supply.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
rrinker Do NOT use the solder hole in the back to transmit power from one to the other, that's just the positive terminal, the ground is still in Loconet when you do that. Radio Shack has the proper size coax plugs, so you cna use a single say 1 amp power supply of 14-15VDC and run two wires to each UP5 and tap off to one of those coax conenctors and plug it in. Beats having a dozen PS14's.You cna apply power to any UR91s and UR92s this samew way, they can share a common power supply. --Randy
Excellent advice, Randy.
If you don't mind, I'll add that those coax plugs are 2.1mm, center positive, and besides the UR's and UP's, they also fit DS64's. I get mine here, if you need more than a couple they're a lot cheaper this way:
2.1mm coax power plugs
Thanks for the info.The amount of RJ12 connections is one of the things that concerns me.I figured that each connection must degrade the signal some. Also we have quitea bit more to add since we're into the signaling system.The DCC on the layout is also about 6-7 years old which I assume could affectthe connection quality of the RJ12's?
In theory, yess, each connector adds a bit of reistence to the circuit. However, the fixed ones under the layout, that you aren't constantly plugging and unplugging like a throttle port, should stay tight for many years. Unless you are using 'unapproved' devices that may put too much load on the Loconet, or lots of unpowered throttles (either batteries in them, even wired ones, or providing power to ALL the UP5's), I still say you will get some many devices that the traffic level will cause response lags before you actually overload the Loconet in an electrical sense.
On the club modular layout we actually have 2 Loconets. One conencts the command station, boosters, and the throttles (UP5, UR91, and UR92). The other is strictly for the signal system which is a mix of components like RR-CirKits Tower Controllers and Team Digital boards. Early on there were too many delayed responses controllign locos when it was all one network, mainly because the signal system is built to modern practices with lots fo flashing aspects. And when JMRI wants to flash a signal head, it constantly sendsout ON and OFF messages. The SE8C can do a 'flashing yellow' as the 4th aspect, which would cut the Loconet traffic since all you need to do is tell the 4th aspect to turn on and the board handles the flashing, but we also have indications with flashign red, and most signals are driven from Tower Controllers anyway, not SE8Cs.