# RBNB™ Web Access Portal Help

## May 21st, 2002

## Copyright Creare, Inc.

## Table of Contents

- Introduction
- Server/Channel Selection
- Request Options
- Release Notes

## Introduction

Welcome to Creare's Web Access Portal! This software allows you to view RBNB channels via your webbrowser. Simply click on the channel you are interested in, and it will be displayed. If the channel has an extension with a MIME type (such as .jpg), the channel will be shown by that type; otherwise, plain text is used. This technology is powered by JSP and Servlets running on a Tomcat servlet host.

For more information on RBNB technology, visit RBNB Home. For more information about servlets, please see Sun's informative white papers located here. For JSP, here. Lastly, for more information about the Tomcat project, a subset of the Jakarta effort, visit their homepage, jakarta.apache.org.

## Server/Channel Selection

The options in this portion of the form determine what entries are displayed in the list to the right of the form.

### RBNB Address

The header form has a field that allows you to enter the Internet Address of the RBNB to which you wish to connect. Be aware that the server which your browser is talking to determines the connectivity of this form; that is, if a webserver is running the WebAccess servlet at Creare, it will not be able to see an RBNB running behind your firewall.

### Channel Match

The Channel Match field specifies which channels available on the connected server are listed in the summary to the left. The default is the ellipsis, "...", which means to include all channels recursively from the root. You may specify "[Source]/...", where [Source] is the name of a data source connected to the RBNB. As of this writing, the use of "..." on lower channel levels is not implemented.

### Keyword Match

The keyword match allows the user to specify that only channels which contain the specified keywords, separated by spaces, within their meta-data should be displayed. This implies that the meta-data needs to be text.

If this field is blank, no search is performed.

## Request Options

The options within this section of the form determine which data the server fetches when the user presses a link.

### Meta or Source Data

This field allows you to select between Meta Data, static data stored on the server in its registration map, or Source Data, dynamic data stored in the ring buffer. If meta data is selected, the next three options (Start, Duration, and Reference) do not apply.

### Start

The Start field allows you to enter a time value at which the data should be acquired. The default units for time is seconds, but can be whatever the data source specified (e.g. incremental counts). The "Reference" value further modifies how time is interpreted (see below).

### Duration

The Duration field determines the amount of data to fetch, in source-units (e.g. in seconds). A value of 0 is a special case, signifying that the single last point (object) of data is to be returned.

### Reference

The Reference field determines how the Start and Duration fields are interpreted, as follows:

- "absolute" -- The start time is interpreted as given by the source without modification. The default is absolute time in seconds from midnight, Jan 1st, 1970 UTC.
- "newest" -- The start parameter is measured relative to the most recent data available in the server. Therefore, start = 0 means current data.
- "oldest" -- The start parameter is measured relative to the oldest data available in the server. Therefore, start = 0 means the beginning of the data.
- "after" -- Return the newest data available, but only the portion after the specified start time. This means you may get a fraction of the duration amount.
- "modified" -- Similar to "after", but it will return a full duration amount of data if any part of the data is after the specified start time.

### Via PlugIn

This field allows you to filter through a PlugIn any channels you select. A popular selection is the PNGPlugIn, which displays time domain vector data as a plot in the Portable Network Graphic format.

## Release Notes

### Updates and Fixes

#### Version 0.1, December 5th, 2001

First release.

#### Version 0.2, December 5th, 2001

Removed version field; no longer supports V1.0 RBNBs.

#### Version 0.5, May 21st, 2002

Added folder display, keyword matching options.

### Known Bugs

Currently, RBNB channels with question marks, ampersands, percent signs, or other characters with special meaning in URLs are not correctly displayed by this Servlet.