How to connect a sequence to a specific IBM 5250 session already opened



Hello ,
We work with AS/400 pc emulator.
Since I have multiple opened session, each having a different one letter Id (from A to Z), I would like to work in a sequence with a specific one (e.g with the session Z)
My connection string of the Terminal Session Activity receives the letter as parameter (argLettreSession) and looks like that :

> “{‘AttachExisting’:false,‘ConnectionType’:2,‘EhllBasicMode’:false,‘EhllDll’:‘C:\Program Files\IBM\Client Access\Emulator\pcshll32.dll’,‘EhllEnhanced’:true,‘EhllFunction’:‘hllapi’,‘EhllSession’:’” + argLettreSession + “’,‘Host’:null,‘Mode’:1,‘Port’:23,‘Profile’:null,‘ProviderType’:4,‘ShowTerminal’:true,‘TerminalType’:0}”

I always receive this message : There was an error connecting to terminal. Error code: Error
And in the log:
13:51:05.6799 warn EhllapiWrapper.CallEhllApi(1) returned 1
13:51:05.7079 error EhllBridge.Attach error : NotConnected
13:51:05.7219 error System.Exception: Error attaching to session
at UiPath.Terminal.Generic.EHLLApi.EhllTerminal.InitializeEhll(ConnectionData connectionData)
13:51:05.7219 error at UiPath.Terminal.Generic.EHLLApi.EhllTerminal.InitializeEhll(ConnectionData connectionData)
13:51:05.7379 warn EhllapiWrapper.CallEhllApi(2) returned 1
13:51:05.7379 error EhllBridge.Detach error : NotConnected

Is there someone with a solution ?