Business service is not working in sender side but business system is working soap to idoc but why like that

i have scenario SOAP to IDOC

when i'm using business service in sender side it is getting an error as follows

sender message can not convert to ALE Logical system

in this i'm using altova spy as testing tool

my sender interface is asynchronous

but when i'm using business system everything is working fine

In sender side i'm using soap adapter,i checked the logical system everything is fine

mainly the problem is why it is working when i'm using business system rather than business service

my pi version is pi 7.0

thanks in advance

regards

satish