Friends, This novice continues to have questions, but this forum has been a great help in learning DCC. I try to read most everything posted. Now, another confusion about the number of addresses available (Digitrax Zephyr = 10) and their use has come up. Several of you explained that one can have far more than 10 locomotives on a layout, but that, given the limit to 10 addresses, only 10 can be running at the same time. I now understand the limits of the command station and locomotive addresses. However, it was recently explained to me (verbally, not on this forum) that when you wire turnouts to the system, that each turnout will be given an address, keeps that address, and reduces the number of addresses that the command station will have available since the address of a turnout cannot be released from the command station. So, if five turnouts are wired to the layout, then five addresses are permanently assigned by the command station to the turnouts, cannot be released, and only five addresses are now available for locomotives. I would appreciate your reaction to this proposed limitation of turnout addresses explained in the paragraphs above. Thank you, Schoolmaster
There are different ways to control turnouts using DCC, depending on the type of "stationary decoder" you use. Some newer turnouts have built in DCC stationary decoders, but I have no experience with these units at present. I use Kato Unitrack powered turnouts and operate them with a Digitrax DS64 stationary decoder. Digitrax.com: Mobile Decoder Menu If you search old threads here you'll find that we've discussed this unit many times. Basically the DS64 has four outputs. You may wire one or two turnouts to each output. If you wire two of them, they switch simultaneously; good for sidings in some cases. On my Digitrax Zephyr I hit the switch button to enter "switching mode". Then I enter "switch address" assigned to the port I want to switch. Finally I hit the "c" (for close) or "t" (for throw) button to operate the turnout. The "exit" button returns me to locomotive operations. I'm not familiar with other DCC systems, but the behavior of the Zephyr and DS64 seems to illustrate that turnout addresses are a separate entity from locomotive addresses. I have had switches addressed to the same numbers as locomotives with no problems. Also, because these aren't locomotive addresses, and don't require control information to be updated continuously, they don't have to be in the locomotive list. If the Zephyr has a limit, its more than the eight switch addresses I've used, while running up to four locos on my layout. I haven't seen the relevant standards documents to know the details. Hope this helps.
Don't worry about tying up mobile decoder slots with stationary decoder address's. They are separate. 10 loco slots are available for mobile decoder address. Stationary decoder address's are handled differently. Since the command needs to be sent only once and not refreshed repeatedly, its address does not occupy a slot. On the other hand, the command station needs to refresh active mobile decoder commands on a regular basis. Mobile decoder slots stay occupied as long as they stay active. e.g. speed above 00 or consisted. Martin Myers
Thank you to MFN and Lownen for their explanations of the use of addresses and turnouts with the Zephyr. Each of you have clarified another aspect of DCC. I am grateful. Schoolmaster
