What is an extended MCS console?

To establish a program as an extended MCS console, the program must issue the MCSOPER macro. Once activated as an extended MCS console, a program can receive messages and command responses by issuing the MCSOPMSG macro, and can issue commands by issuing the MGCRE macro. Unlike a standard MCS console, the extended MCS console can control which command responses it receives.

To receive messages and command responses, a program must issue the MCSOPMSG macro. Parameters on the MCSOPMSG macro enable a program to receive only specific types of messages. Receiving messages and command responses, and issuing commands describes some of the parameters on the MCSOPMSG macro.

To receive the hardcopy message set, a program must issue the MCSOPER macro with REQUEST=ACTIVATE and the HARDCOPY attribute specified in the OPERPARM parameter list. Receiving the hardcopy message set describes how to do this.

To issue commands, a program must issue the MGCRE macro. For more information on the MGCRE macro, see Issuing operator commands from a program (MGCRE macro).

In a sysplex, an extended console application can receive messages from any system or systems in the sysplex, or can send commands to any system or systems in the sysplex. There is no system-imposed limit on the number of extended MCS consoles.

Extended MCS consoles will consume system resources, whether active or inactive. Once an extended MCS console is activated, the console definition remains for the life of the sysplex, even if it is later deactivated. IBM recommends care in the definition and use of extended MCS consoles, because an application that makes inefficient use of extended MCS consoles can cause system performance degradation. Specifically, an application should make use of existing extended MCS consoles, rather than defining new consoles. With z/OS® V1R7, you can remove the definition of an unneeded EMCS console by using the sample program IEARELEC, which is shipped in SYS1.SAMPLIB. See z/OS MVS Planning: Operations for a description of this program and how to it.

If the application does not need to receive messages from all systems in the sysplex (or only some of the systems in the sysplex), the MSCOPE of the console can be changed to reduce the amount of message traffic that the console receives.

See Example of managing an extended MCS console session for sample code for an extended MCS console. Sample code that shows how to use an extended MCS console resides in IEAEXMCS in SYS1.SAMPLIB.

You can use a security product such as RACF® to protect the use of extended MCS consoles. For more information on using RACF for this purpose, see z/OS MVS Planning: Operations.

This information refers to several data areas and some of their fields. The data areas and their mapping macros are:

All of these data areas and their fields are documented in z/OS MVS Data Areas in the z/OS Internet library.