Adding Communications Computer in SNA Net Can Offer More-timely Data

The prospect for integrating communications networks that employ the full capability of IBM's SNA (Systems Network Architecture) and non-IBM peripherals have never appeared better.

This article centers on communications between non-IBM point-of-sale terminals in large retail stores and an IBM SNA host. The applications, however, go beyond retail transactions to any highly interactive mixed-peripheral communications network. The application described here also applies to banking, manufacturing, wearehousing and institutional environments.

Point-of-sale terminals, or POSTs, are attached to in-store concentrators that communicate with a communications computer (microcomputer). Over a multi-drop leased-line network, the communications computer transmits data to an IBM host through a front-end processor. In the store, the computer controls printers and terminals for total inquiries, data colection, credit inquiries and responses, report requests and report generation.

The typical in-store transaction consists of an information stream that includes POST identification, employee number, items being sold and their prices and, if applicable, the credit card number: This POST data can be pre-processed and transmitted to the host. Selected HOST data is held in the computer and processed for employee and department daily totals, items important for the store's sales incentive program. Speedy Authorizations

The communications computer, which can gather data from hundreds of POSTs, supports the POST concentrator protocol and the IBM SNA protocol. Credit-authorization transactions are given priority over data-collection transactions that are batched to provide better network and processing performance. The store's card is checked against the host's data base for credit authorization. Third-party cards, such as American Express, Visa or MasterCard cause an inquiry over leased lines to the third-party's data-processing center. Transactions are automatically verified in just a few seconds and the sales clerk and customer are spared the time and difficulty of a separate phone call to get credit authorization.

During the day, the host will process and log transactions. All transactions are dated and time-stamped, and logged to a redundant mirror-image file. In the evening, the host will process data, update inventory and sales information and post transactions for the store's credit cards. It then sends a complete, audited transaction report to an in-store printer.

During low-activity hours, the host can transmit updated sales and inventory information for each department to the communications computer. Print spooling allows rapid data transmission to the store and subsequent slow-speed printing at each store without tying up communications facilities or the host processor.

The communications network is controlled by both the host and the communications computer. Network control overhead is costly in terms of performance. In unison with the host, the communications computer will batch POST transactions when the host CICS transaction burden grows too large. Acting as a real-time throttle, it maintains the quality and flow of data from its store to the host and adjusts the number of POST data transmissions per CICS transaction. The host, with more free processing power, is able to transact individual items more quickly and provide expeditious processing of corporate financial and management reports.

To reduce host loading, certain transactions are processed within the store. The communications computer can pre-process POST data by combining separate POST data fields into one transaction. Each salesperson has access from any POST to his or her individual sales totals for the day. The store manager has access to department and store totals.

In the event the leased line goes down, the communications computer stores transactions while the POST operates in a local mode. If necessary, overflow is routed to the POST concentrator. While credit verification would have to be done by telephone, all other aspectes of the system from the customer's point of view are business as usual.

The SNA system just described can allow a large retailer or other institution to provide better service for its customers as well as more accurate and timely data for its managers and employees. By implementing a communications computer into their system, a company is able to preseve a large investment in POSTs and employee training, and extend their productive life. This type of system provides in-store data-processing capability and a better way to manage the communications network, thus increasing the speed and efficiency of customer service provided by the retailer.

COPYRIGHT 1984 Nelson Publishing
COPYRIGHT 2004 Gale Group