Original post over in the N scale forum, but I should've posted here first. Sorry... Locomotive: Atlas 4-4-0, ESU LokPilot Standard Nano System: DCC++, Arduino Uno, Arduino Motorshield, Dedicated program track for testing Software: JMRI, DecoderPro, PanelPro Problem: Getting error message 308 - No acknowledge from locomotive, when trying to read or write to decoder through DecoderPro. Situation: The initial setup, where I add new loco to the roster, won't automatically read the decoder. So I manually select the decoder from the list and start the entry using the ESU setting below the list (sorry I forgot to screenshot it). I create the roster entry. The locomotive can be controlled via JRMI throttle. But everytime I try to read the decoder or make a change to it, I get Error 308 - No acknowledge from locomotive. Obviously there's power to the track and the loco can receive commands. But the speed table is very unrealistic for this engine and I'd like to be able to improve the slow speed start/creep. Much of the time, trains in this era only traveled like 15 miles per hour. I know there are some other threads on here about similar situations. But I'm very sorry to say I'm not at all familiar with this stuff. Jumping into one of those threads and trying to make sense of it is nearly impossible for me. If anyone out there can offer some guidance, or direct me to someone who would know a little more about this, I'd be very grateful for the assistance. As you can expect, I'm very excited about getting DCC++ up and running, even if just the program track for now.
Hi MVP For me programming on the Main Line using DCC++ and JMRI always gives me this error. I only use Programming on the Programming Track mode and that combination usually works for me. Programming on the Main Line has some issues as there is no current limiting function and if there is a problem with the installation of the decoder it can draw sufficient current to damage the decoder, usually fatally. For the Programming Track it is usual to put a current limiting series resistor so that the decoder can only draw sufficient current to programme the decoder an not enough current to damage the decode on a short etc. I am using a 27ohm, 25W series resistor on my DCC++ Programming Track PWM output to limit the current when programming the decoders, seems to works OK, I burnt out a 1W resistor with a Broadway sound card equipped loco so when for a OTT resistor wattage to make sure it survived. Hope this held DaveT Kuala Lumpur
Some of that went over my head. I'm using only a program track. Is there a walk-thru of using a resistor on this? As I said, I don't really know anything about this stuff. And combing through forum threads with dozens of dense replies isn't very helpful.
Can you double check your settings? There is an option to have programming on internal, that may trip you up. Also, if all you have is a programming track and you can drive the loco, you aren’t using a programming track, your wires are going to main instead. That will always cause 308 error.
Yup. I'm an idiot. The answer was right in front of me. The wires were in the main, not the program. Seems to be reading and writing just fine now. Thanks. However, the engine seems to run as if it were on DC and I was surging and slowing the trottle. Slower then faster, with no slow speed crawl. I've tried adjusting the speed table, but I'm not all that familiar with it yet. I'll keep reading.
No worries, glad we got it diagnosed! Only thing I can suggest is use the full speed table and not the 3 step, especially with the older locomotives you run.
