there are a lot of variables that could be at play here.. it could be that the field you are scanning is has an attribute to send the data.. if that is the case, then the change will need to be made on the server side.. there are a few variables with in TE that can have this affect as well..
please check the following areas in the emulation parameters:
Auto Send Screen:
Auto Send Key Data
ScanHandlers that maybe be sending the data
You're going to need to create a custom ScanHandler Script that contains the following pseudoCode. I could have easily written out the exact script for you but thats your job to figure out!
Activate On Scan
Global String FirstScan
If ScanType ! = GS1-128
//Pass through the scan data automatically if its not a GS1 type barcode
//If you have previously scanned a GS1 barcode
If FirstScan == ""
//Send the combined first and second scans
SendScan(FirstScan + ScanData)
//Clear the stored scan information
FirstScan = ""
//Assuming that this is the first of two scans, save the scandata into a global variable and then return. The global variable will be referenced once the script is triggered again.
FirstScan = ScanData