The openUTM application sends information on the transaction and service state to the client with each user message. The CPI-C application can read this information using the Extract_Transaction_State call.
The state information is sent in a 4-byte field. The first two bytes indicate the state of the service and transaction, the second two bytes supply diagnostics information, see section “Extract_Transaction_State - Querying service and transaction state of the server”. The program can therefore detect, for example,
whether the processing step was completed with or without transaction termination,
whether the service was also terminated, or
whether the transaction was rolled back.
The CPI-C program can respond appropriately and, for example, provide detailed information on whether input was accepted successfully or whether input must be re-sent to the server because the transaction was rolled back.