ICF Prestart Job

I am trying to change a process that uses ICF to get account information 
from another system so that the target programs is a prestart job. 
However, I know very little about ICF.  The target program is evoked 
thousands of times a day and has become a resource hog.    Basically how 
the process works is that source program evokes the target programs and 
sends parms.  The target program acquires the ICF device, receives the 
parms, does some processing, sends back summary data, writes a detach and 
ends. 

According to the ICF programming manual you have to do an end-of-session 
function so that the program will wait acquire a new program device.  I 
tried just writing a EOS after the detach but get errors that the session 
ended abnormally.    Does any know how to make this work or have an 
example they would be willing to share? 

Thanks.

Mark Garton
Information Systems
O'Reilly Auto Parts