Connect Window Services (101)

The Connect Window Services function allows the application to manage the presentation space windows. Only one EHLLAPI application at a time can be connected to a presentation space for window services.

An EHLLAPI application can connect to more than one presentation space concurrently for window services.

3270	5250
Yes	Yes

Prerequisite Calls

There are no prerequisite calls for this function.

Call Parameters

	Standard Interface	Enhanced Interface
Function Number	Must be 101
Data String	1-character short session ID of the host presentation space
Length	1 is implied	Must be 4
PS Position	NA

The calling data string can contain:

Byte		Definition
Standard	Enhanced
1	1	A 1-character presentation space short name (PSID)
	2-4	Reserved

Return Parameters

Return Code	Explanation
0	The Connect Window Services function was successful.
1	An incorrect host presentation space short session ID was specified, or the Sessions Window Services manager was not connected. This return code could also mean that the API Setting for DDE/EHLLAPI is not set on.
9	A system error occurred.
10	The function is not supported by the emulation program.
11	This resource is unavailable. The host presentation space is already being used by another system function.

Remarks

An EHLLAPI application can be connected to multiple presentation space windows at the same time. The application can go back and forth between the connected presentation space windows without having to disconnect. For example, if an application is connected to presentation space windows A, B, and C, the application can access all of A, B, and C at the same time, and the other applications cannot access A, B, or C.

A Connect Window Services function is sufficient for the process. However, each thread that requests a Connect Window Services must have a corresponding Disconnect Window Services (102), or one of the threads must issue a Reset System (21), which affects all threads and disconnects any remaining connections.