What is an OTMA client?

An OTMA client is a z/OS® application program that sends transactions to an IMS server and receives output. The application program must be a member of an z/OS cross-system coupling facility (XCF) group and use the OTMA protocol.

Heterogeneous (non-z/OS) networks can connect with z/OS in many ways. The following figure shows some of the possible applications that use XCF. These include:
  • IBM® MQ applications
  • OEM applications
  • IMS Connect applications
  • DCE/RPC applications
  • Other IBM applications

Any of these can connect to an OTMA client to communicate with IMS.

Figure 1. Applications that use XCF to connect to IMS on z/OS
Each application (OTMA client) listed above connects to IMS and the OTMA server through an XCF group.

An OTMA client is the gateway by which transactions from outside IMS can enter IMS.

OTMA processing involves:

  1. A client sends a transaction or command to the server (IMS).
  2. The server returns output to the client.