acknowledgement not possible error

Hi Friends,

I have a scenario from IDOC to FILE, upto this part message is processing successfully. The message getting failed in moni when it receives acknowledgment with ack.status as acknowledgement is not possible and after opening the message in the error log it is showing as unable to convert the sender service to an ALE logical system.

queries:

1. is acknowledgment is possible for this scenario(any either system or application acknowledgement) .

2.If possible, could you please let me know the procedure for the same.

Regards,

Janardhan