The following can communicate to an application by way of a NOF program:
An external program
A non-intelligent, external terminal
The figure below illustrates this interface method.
NOF Programmatic Interface
The NOF program is a user-written COBOL program that performs a similar function to the logic you would provide in an intelligent terminal.
After receiving a transaction from an external source, the NOF program performs the following process:
Constructs the transaction in the format required by the application
Passes the transaction to the application for processing
Constructs the unformatted output from the application into the format required by the initiating program or terminal
The NOF program might also receive a transaction initiated by the application. This is passed to the appropriate external system, and a reply is passed back to the application.
Input from the NOF program to the application is treated in the same way as input from a NOFORM-type terminal, except that replies are returned to the NOF program.
If the terminal is a Cluster Master, it must keep track of which terminal initiated any given transaction.
This programmatic method is thus multithreading, enabling more than one transaction to be processed at a time.