HP NonStop G-Series - Manual (Page 29)

2 Workstation Configuration
110838 Tandem Computers Incorporated 2–1
You must configure the Tandem DDE Gateway before you use it to access the Tandem
system. The Tandem DDE Gateway views the environment in which it operates as a
set of “objects” of various categories. You can name the following categories of
Tandem DDE Gateway objects and assign them attributes with configuration files
(“INI” files) on the workstation:
ApplicationName objects represent the client application’s view of the application
environment. You associate an ApplicationName with a PortName (“how to get
to the application server’s Tandem system”) and an application environment
within that Tandem system (or Expand network). The application environment is
usually a Pathway environment identified by the name of its PATHMON process.
PortName objects represent a data communications connection to a Tandem
system. A PortName is associated with a data communications resource such as a
NetBIOS LAN or a workstation asynchronous port.
ServiceName objects represent individual transaction types (such as “read an
employee record”). You associate ServiceName objects with a Pathway server
class or a Guardian process. You can also give a ServiceName object an attribute
that identifies whether a Remote Server Call (RSC) interprocess session or an
Intelligent Device Support (IDS) session will be used when a message is sent to the
Tandem server.
When you want to perform a transaction from a client application, use the DDE
Execute function with the INITIALIZESERVICE command. This command has one
required parameter, a ServiceName, and an optional ApplicationName as shown in
the following examples:
[INITIALIZESERVICE(READ-EMPLOYEE, PAYROLL)]
[INITIALIZESERVICE(ORDER-STOCK)]
The Tandem DDE Gateway uses the ApplicationName you specify to find the
appropriate data communications resources and to access the correct Pathway
environment (the ApplicationName is associated with a PortName and a Pathway
environment). If the ApplicationName is omitted, then an ApplicationName of
DEFAULT is used.
Figure 2-1 shows a client application that uses two data communications connections
to perform two transaction types in separate Pathway environments. In the second
transaction all defaults are used.