When the length of the communication area (EIBCALEN) is equal to zero, it means that no data was passed to the application.When working in the pseudo-conversational mode, EIBCALEN can be checked for zeros as a way of determining the first time usage of the program.The OPNAME and PASSWORD defined in the SNT must be provided for this transaction.
Therefore to reduce data transmission, when the first time the map is sent, MAPONLY option must be used, because this will set up the initial template on the screen.
After that, the application needs to send only the variable data in the symbolic map using DATAONLY.
A HANDLE CONDITION command specifies what should be done when the specified condition occurs.
Or it is equivalent to a conditional 'go to' statement.
The INTO option moves the information in the TIOA into the reserved specified area, while the SET option simply returns the address of the TIOA to the specified BLL cell or 'address-of' a linkage section.
When defining the map field using DFHMDF macro in the attribute parameter if IC is coded, the cursor will be positioned in that field.
This method of cursor positioning is called static cursor positioning.
A vast majority of the maps are defined as input/output.
Terminating the task every time the application needs a response from the user and then starting the next transaction when the user presses any attention key is pseudo conversational processing.
The XCTL command transfers control to another application having the same trans id but the START command initiates a new transaction.