Specifications

Introduction
193
Outdial TAP Networking
Introduction
TAP is the Telocator Alphanumeric Protocol, which is used for entering alphanumeric
pages into paging terminals. Outdial TAP is an implementation of TAP for Zetron paging
terminals that is used to send display pages from the Zetron terminal to other paging
terminals that support TAP input. In the context of Outdial TAP, a display page is any page
that does not contain a voice message as part of the transmitted page, thus “tone only”
pages are considered to be display pages even though there is no actual display message.
Outdial TAP requires the outdial TAP peripheral card and supporting software. It
generally would be used with a standard end-to-end phone line and Hayes compatible
modem.
Up to 16 paging terminals may be selected as outdial TAP destinations. A subscriber may
have any one, or any combination of the 16, assigned as the target for pages.
Outdial TAP is intended for sending a small to medium volume of display pages from one
terminal to another. It may be used to extend the coverage region for some users of an in-
plant paging system, by calling up an external paging service. Outdial TAP also may be
used as a concentrator for display paging, allowing an outlying Zetron terminal to collect
and forward display pages to a main paging system.
Outdial TAP has been used to send pages to Zetron Series 2000 terminals, Model 640s,
and a Model 16 equipped with a Hayes compatible modem. It also has been used to place
pages on other vendors’ paging terminals. Both Network USA and Skypage support alpha
access and have been successfully called using outdial TAP.
TAP is best suited to applications where only a moderate number of pages need to be sent.
As a phone call must be placed and modem connection established, an outdial TAP
connection may have as much as 20 seconds or more of overhead time. In addition, many
TAP installations support only 300 baud data transfers, and few sites support any rate
faster than 1200 baud. This limits the number of pages that may be sent in any given
period, especially if the pages have long display messages. Outdial TAP does not support
capcode paging, or the sending of function codes or priority levels.