Single physical vehicle apparently represented by multiple TrainIds

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1

Hi,

after checking our TrackerNet data logs, we found the following messages (for Totteridge & Whetstone):

2020-04-09 15:41:03
      <T LeadingCarNo="0" LN="N" TrackCode="TN50371" IsStalled="0" Direction="0" Departed="0" DepartInterval="194" DepartTime="14:40:56" Order="0" DestCode="308" InputDest="MOR5-Y (MOR5-Y//MOR5-Y) [=MOR5/MOR5=Y]" Destination="Morden via Bank" Location="At High Barnet Platform 2" TimeTo="3:30" SecondsTo="194" TripNo="0" SetNo="000" LCID="21" TrainId="11445572"/>

2020-04-09 15:41:33
      <T LeadingCarNo="0" LN="N" TrackCode="TN50371" IsStalled="0" Direction="0" Departed="0" DepartInterval="194" DepartTime="14:41:23" Order="0" DestCode="308" InputDest="MOR5-Y (MOR5-Y//MOR5-Y) [=MOR5/MOR5=Y]" Destination="Morden via Bank" Location="At High Barnet Platform 2" TimeTo="3:30" SecondsTo="194" TripNo="0" SetNo="000" LCID="21" TrainId="11446772"/>

2020-04-09 15:42:03
      <T LeadingCarNo="0" LN="N" TrackCode="TN50371" IsStalled="0" Direction="0" Departed="0" DepartInterval="194" DepartTime="14:41:30" Order="0" DestCode="308" InputDest="MOR5-Y (MOR5-Y//MOR5-Y) [=MOR5/MOR5=Y]" Destination="Morden via Bank" Location="At High Barnet Platform 2" TimeTo="3:30" SecondsTo="194" TripNo="0" SetNo="000" LCID="21" TrainId="11445572"/>

2020-04-09 15:42:33
      <T LeadingCarNo="0" LN="N" TrackCode="TN50371" IsStalled="0" Direction="0" Departed="0" DepartInterval="194" DepartTime="14:42:19" Order="0" DestCode="308" InputDest="MOR5-Y (MOR5-Y//MOR5-Y) [=MOR5/MOR5=Y]" Destination="Morden via Bank" Location="At High Barnet Platform 2" TimeTo="3:30" SecondsTo="194" TripNo="0" SetNo="000" LCID="21" TrainId="11445572"/>

2020-04-09 15:43:03
      <T LeadingCarNo="0" LN="N" TrackCode="TN50371" IsStalled="0" Direction="0" Departed="0" DepartInterval="194" DepartTime="14:42:56" Order="0" DestCode="308" InputDest="MOR5-Y (MOR5-Y//MOR5-Y) [=MOR5/MOR5=Y]" Destination="Morden via Bank" Location="At High Barnet Platform 2" TimeTo="3:30" SecondsTo="194" TripNo="0" SetNo="000" LCID="21" TrainId="11446772"/>

2020-04-09 15:43:33
      <T LeadingCarNo="0" LN="N" TrackCode="TN50360" IsStalled="0" Direction="0" Departed="0" DepartInterval="176" DepartTime="14:43:27" Order="0" DestCode="308" InputDest="MOR5-Y (MOR5-Y//MOR5-Y) [=MOR5/MOR5=Y]" Destination="Morden via Bank" Location="Between High Barnet and Totteridge &amp; Whetstone" TimeTo="3:00" SecondsTo="176" TripNo="0" SetNo="000" LCID="21" TrainId="11445572"/>

2020-04-09 15:44:03
      <T LeadingCarNo="0" LN="N" TrackCode="TN50342" IsStalled="0" Direction="0" Departed="0" DepartInterval="140" DepartTime="14:43:54" Order="0" DestCode="308" InputDest="MOR5-Y (MOR5-Y//MOR5-Y) [=MOR5/MOR5=Y]" Destination="Morden via Bank" Location="Between High Barnet and Totteridge &amp; Whetstone" TimeTo="2:30" SecondsTo="140" TripNo="0" SetNo="000" LCID="21" TrainId="11446772"/>

2020-04-09 15:44:33
      <T LeadingCarNo="0" LN="N" TrackCode="TN50324" IsStalled="0" Direction="0" Departed="0" DepartInterval="104" DepartTime="14:44:22" Order="0" DestCode="308" InputDest="MOR5-Y (MOR5-Y//MOR5-Y) [=MOR5/MOR5=Y]" Destination="Morden via Bank" Location="Between High Barnet and Totteridge &amp; Whetstone" TimeTo="2:00" SecondsTo="104" TripNo="0" SetNo="000" LCID="21" TrainId="11445572"/>

2020-04-09 15:45:03
      <T LeadingCarNo="0" LN="N" TrackCode="TN50300" IsStalled="0" Direction="0" Departed="0" DepartInterval="56" DepartTime="14:45:01" Order="0" DestCode="308" InputDest="MOR5-Y (MOR5-Y//MOR5-Y) [=MOR5/MOR5=Y]" Destination="Morden via Bank" Location="Between High Barnet and Totteridge &amp; Whetstone" TimeTo="1:00" SecondsTo="56" TripNo="0" SetNo="000" LCID="21" TrainId="11445572"/>

2020-04-09 15:45:33
      <T LeadingCarNo="0" LN="N" TrackCode="TN50282" IsStalled="0" Direction="0" Departed="0" DepartInterval="21" DepartTime="14:45:30" Order="0" DestCode="308" InputDest="MOR5-Y (MOR5-Y//MOR5-Y) [=MOR5/MOR5=Y]" Destination="Morden via Bank" Location="Between High Barnet and Totteridge &amp; Whetstone" TimeTo="0:30" SecondsTo="21" TripNo="0" SetNo="000" LCID="21" TrainId="11446772"/>

2020-04-09 15:46:03
      <T LeadingCarNo="0" LN="N" TrackCode="TN50270" IsStalled="0" Direction="0" Departed="0" DepartInterval="0" DepartTime="14:45:53" Order="0" DestCode="308" InputDest="MOR5-Y (MOR5-Y//MOR5-Y) [=MOR5/MOR5=Y]" Destination="Morden via Bank" Location="At Platform" TimeTo="-" SecondsTo="0" TripNo="0" SetNo="000" LCID="21" TrainId="11445572"/>

2020-04-09 15:46:33
      <T LeadingCarNo="0" LN="N" TrackCode="TN50269" IsStalled="0" Direction="0" Departed="0" DepartInterval="0" DepartTime="14:45:47" Order="0" DestCode="308" InputDest="MOR5-Y (MOR5-Y//MOR5-Y) [=MOR5/MOR5=Y]" Destination="Morden via Bank" Location="At Platform" TimeTo="-" SecondsTo="0" TripNo="0" SetNo="000" LCID="21" TrainId="11446772"/>

It looks like these are messages for one physical train, but the TrainId field seems to be randomly alternating between 11446772 and 11445572, while the LCID field stays the same.

Does anyone know what is the explanation for this behaviour? What does the TrainId field represent exactly?

It seems that the LCID field is more reliable. Can anyone confirm whether it’s really distinct across all trains of a given line (as it presumably should be)?

Thanks.

2

LCID is “The leading car Id for the train”

I’m not sure quite where your assumption comes from. TrainID isn’t one of the documented fields - see http://content.tfl.gov.uk/trackernet-data-services-guide-beta.pdf page 34. I think it’s just one of those things to be used “as is”. Whatever it is, it is.

3

Braintist is correct. It’s whatever you see.

It depends on the line. Some lines have control systems that pass a unique ID to TrackerNet, some don’t.

Some lines have recently gained the ability to pass a unique ID to TrackerNet but TrackerNet may not have been updated to process it.

Until all lines have been brought up to the same standard I guess it won’t become a documented feature.

4

Thank you, so far using the LCID seems to work fine.

Regarding the TrainID field, the field was noted here: IMPORTANT INFORMATION FOR TRACKERNET USERS - Change to data format

However, in the Trackernet XML feed, the unique Train ID is incorrectly listed under the “LCID” field for the same train
There will be a new field for TrainID which will have the value that’s currently in the LCID field.
You should amend your apps to ingest the new TrainID field rather than the LCID field

We tried to use TrainID but as it’s not reliable we are simply using LCID instead.