Many of today's server-based applications are developed to utilize the sophisticated graphical capabilities of PC's or workstations for user input and display. This was not always the case, and traditionally, most NonStop Server-based (aka Tandem) and mainframe applications made use of "green-screen" terminals, such as the Tandem 6530 or IBM 3270, as their primary user interface device. Examples NonStop applications include Logica's BESS product, ACI's BASE24 product and Phamis Lastword (now GE Centricity).
Many of these legacy systems, designed with block-mode interfaces, are still in use. They continue to be maintained and so adequate testing remains an essential part of the process. Testing is generally a case of manually entering many screen-based transactions and verifying the responses as they are received. The testing staff spends hours laboriously keying in tests, checking results and then re-keying tests which need to be repeated.
Automating the Testing of Block-mode Applications
VersaTest's VTERM Terminal Simulator, an add-on module to VersaTest™, automates this expensive, time consuming and error prone process. The Standard VersaTest product can interface with block-mode applications and capture any existing terminal traffic. VTERM takes this a stage further by applying intelligence to the traffic, allowing it to simulate the operation of 6530 and 3270 terminals. The simulation is controlled by exposing primitive operations within VersaTest Classic or VersaTest Automator. This allows test scripts to become "virtual operators" of the terminals.
Significant benefits are realizable using VersaTest Automator in particular, since it has an inbuilt ability for Drivers to communicate, so permitting end-to-end testing. For example VTERM running as a DFS Driver within a VersaTest Automator environment can be used to initiate a SWIFT wire transfer via Logica's BESS product. Another DFS Driver simulating the SWIFT network can then verify the received wire against the information entered into BESS - true end-to-end testing.
Advantages of using VTERM for Green-Screen Testing
VTERM sits at the communications level and understands all the subtleties of the Tandem 6530 and IBM 3270 terminals - it avoid synchronization issues common in PC-based simulators. Other advantages include:
- Enables accurate, repeatable testing of traditionally error-prone activities.
- Able to participate in end-to-end test environments.
- Simple one-time process automatically creates test cases without manual coding.