Digitrax LNWI, UR93/UR92 with DT402D/500D/602D Throttles

There is a lack of good information available today concerning Digitrax’s LNWI (WiFi module) and how it works when used with the UR models and throttles mentioned in the title in various combinations with one another.

Specifically, this discussion will cover the LNWI when used with the UR93 alone and when used with a combination of the UR92 and UR93. For details of the LNWI used with a standalone UR92 and DT402D or DT500D refer to the previous post which talks about this explicitly. Peculiarities with the different throttles will be included as necessary. The LNWI’s performance (WiFi channel number and Loconet group name) was checked with the smart phone android app Engine Driver. This app also served to insure control was obtained by manipulating a locomotive.

UR93 Standalone

The DT602D controlled all three aspects of the UR93, group name, channel number and key (password key) via the duplex menu provided by the throttle. Pressing Update made any changes to the UR93 and also updated the LNWI to the same values (channel number and group name and key).

In order to test locomotive control with the DT402D and DT500D untethered, it is absolutely necessary to update your UR93’s firmware to at least the update dated April 5, 2021. This is available on Digitrax’s web site here. Without this update the throttles cannot talk to the UR93.

Note:
As discussed in this previous post the Author’s DT500D is not able to change the channel number of the UR93 and in this case, his results with the DT402D were completely unpredictable at best (has anyone gotten this to work? Please leave a comment if you have). This may be fixed in a future firmware update but how many resources does Digitrax want to put into out-of-production throttles?

Utilizing the standard Digitrax procedure, changing the group name and pressing Enter will update the LNWI. If the channel numbers between the UR93 and LNWI happen to be different the LNWI will not function properly as shown in the table below. Change the LNWI channel number via its op switches (detailed here) to match the UR93 if you do not have a DT602D to do it.

Note:
The author has been told by more than one individual that newly received LNWIs when plugged into a UR93 will work properly with both different group names and channel numbers. He was not able to reproduce this.

Here are the tests results.

Group Name	Channel Number	LNWI Result
Different	Same	Controlled locomotive
Different	Changed to different	No control
Changed to same	Changed to same	No control until LNWI was repowered then was able to control locomotive

 UR92 Standalone with a DT602D Throttle

The DT602D was able to make any and all changes to the UR92 and attached LNWI via the duplex menu.

UR92 and UR93 Combinations

Note:
The author does not recommend you utilize a UP5 panel to connect and make adjustments to UR92/93 combinations. During testing he plugged a 602 and a 500 throttle into the same UP5 and received different results on their displays. This is obviously due to timing differences between the throttles and URs and which UR answered which DT. Plug the throttle directly into the UR you are manipulating.

Utilizing a DT602D to update a UR93 via the Duplex menu will update connected UR92s and any connected LNWIs to the values specified in the menu when the Update button is pressed. In the author’s tests he found it may be necessary to update more than once. Regardless, give Loconet a little time to catch up.

A DT500D or DT402D throttle plugged into a UR92 to update values will also update an attached UR93 and LNWI as long as the Enter key is pressed to complete the update. Just plugging it in and changing values will not update anything.

The author swore he would not “go down the rabbit hole”¹ of plugging differently configured UR92s and UR93s into a properly configured circuit to see which one would override the other (if at all) and the resulting problems (or not) with the LNWI. What has been accomplished here so far took a lot of time away from family. Volunteers???

Recommendations

Follow the instructions in the section that contains your configuration (this includes the prior post here) and you should be set and ready to go.

The author hopes this research clears up a lot of misunderstandings concerning the LNWI and its workings with Digitrax’s other components. With the newer products that have recently been put on the market along with the older components still in use, and they will be for a long time (how many of us still use a DCS100?), things can get a bit complicated. The author can only hope this helps.

In the future, the author plans on presenting monitored Loconet printouts with the various throttles and URs to possibly show timing between the various components and what that may demonstrate (if anything).

1 This is a well known term in the computer field meaning a complexly bizarre or difficult state or situation conceived of as a hole into which one falls or descends.

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