The following 3270/5250 Support components allow you to create an ESL interface to a 3270/5250 application.

The ECS include file defines ESL internal subroutines and declares ESL external subroutines that are specific to the 3270/5250 environment. It also defines ESL variables and constants used by the ECS subroutines. These subroutines perform the following types of tasks:

•Read the contents of the screen buffer into an ESL textual region.

•Read a line into a string variable.

•Read a field's contents into a string variable.

•Write the contents of a string variable to a field.

•Send information to the host.

•Simulate the pressing of a 3270/5250 terminal's special function keys.

•Provide tools to synchronize your ESL application with the host.

The Esl Fields utility provides you with essential information about each field on the current screen in the 3270/5250 screen buffer.

It also generates reports to assist you in the development of the host communications portion of your ESL application.