BMCXLINK provides communication from ISPF and batch to the IMS control region (or regions). Communications between ISPF, batch, and BMCXLINK use VTAM communications. Communications between BMCXLINK and the IMS control region use the cross-system coupling facility (XCF).
Therefore, ISPF and BMCXLINK do not have to reside on the same MVS image. This flexibility allows a single point of control for systems in an IMSPLEX and facilitates coordinating changes across the IMSPLEX. BMCXLINK can be started and stopped asynchronously with IMS.
BMCXLINK maintains an internal trace of all important activities. The trace is always active, can be printed on-demand, and appears in SVC dumps. The minimum size of the trace table is 16 KB, but you can expand it if necessary.
The BMCXLINK started task specifies a VTAM ACBNAME as parameter data in the JCL. When started, BMCXLINK opens the VTAM ACB and permits logons. BMCXLINK then waits for input from an ISPF or batch user. When an input is received, the following sequence of events occurs:
The PLU notifies BMCXLINK.
BMCXLINK retrieves the data and uses XCF to send the request to the appropriate IMS control region (or regions).
The IMS control region processes the request and sends the output back to BMCXLINK through XCF.
After processing the output, BMCXLINK sends it back to the ISPF or batch user through VTAM communications.