simulator with crystal.xml rejects AARQ

By P3NCYUYkUtQkKX64H , 24 January, 2025
Forums
Gurux.DLMS

i'm running the c# simulator with the following parameters:

-i WRAPPER -h 127.0.0.1 -p 4060 -t Verbose -x crystal.xml

my client is sending
RX: 00 01 00 10 00 01 00 12 60 10 A1 09 06 07 60 85 74 05 08 01 01 A9 03 02 01 01

and the simulator is responding with
TX: 00 01 00 01 00 10 00 26 61 24 A1 09 06 07 60 85 74 05 08 01 01 A2 03 02 01 01 A3 05 A1 03 02 01 01 A7 03 02 01 01 BE 06 04 04 0E 01 06 02

it looks like the root cause is this 'return' in GXAPDU.ParseApplicationContextName():

if (settings.AssignedAssociation != null)
{
if ((byte)settings.AssignedAssociation.ApplicationContextName.ContextId == name)
{
return ApplicationContextName.Unknown;

both the client & server's ContextId is '1' (as you can see in the BER). but i don't understand why this is being rejected.

Kurumi

1 year 9 months ago

Hi,

Your client is not sending the correct AssociationRequest and the server rejects it.
Lots of values are missing from the client message and you need to check that.

BR,
Mikko

P3NCYUYkUtQkKX64H

1 year 9 months ago

i'm stepping through the request parsing in the simulator and it's the line above that it's stopping on. can you tell me why it's returning 'Unknown' when the last byte of the passed ApplicationContextName is '1' ? i checked the other versions of the simulator and none of them have this check, and i can't find any justification for it in the IEC spec.