# Using the Telemetry Console Extension

# Working with Metrics Charts and Graphs

Metrics charts and graphs plot the values of metric attributes. The values are real-time polled telemetry data values obtained from a running RFID Edge Server.

To create charts and graphs based on metrics data, you drag metrics attributes from the Metrics tab to the View panel. Each new graph shows the value of the selected attribute over time.

The following sections describe metrics charts and graphs:

- How Metrics Data is Collected and Presented
- Available Edge Server and Reader Telemetry Metrics
- Selecting a Server
- Understanding the Contents of the Metrics Tab
- Displaying Items in the Metrics tab
- Displaying Details About Instances and Attributes in the Metrics Tab
- Displaying Details About Metrics Charts and Graphs

For general information about working with charts and graphs, see Working with Charts and Graphs.

## How Metrics Data is Collected and Presented

When a view containing one or more metrics charts is activated in the Telemetry Console Extension, data collection for viewing those metrics in real time is started on the server. The data is gathered continually and placed in a "wrap-around" cache. That is, as new data fills the cache, the oldest data in the cache is lost. When a view is stopped (see Starting and Stopping Data Collection for Charts in a View), data collection for the contained charts is stopped.

To display current data, the Telemetry Console Extension periodically polls the data cache for a current data set and displays it in a chart.

Note: | The size of the data set returned to the client is configurable. See Setting Global Properties.

## Available Edge Server and Reader Telemetry Metrics

Edge Server telemetry metrics display information about the number of event and programming cycles that have completed within the specified telemetry interval. For information about event cycles and programming cycles, see Reading and Writing Tags in Programming with the ALE and ALEPC APIs.

Edge Server metrics include:

- EventCyclesCompleted—shows the number of event cycles completed within the specified telemetry interval. When the telemetry interval is very short, this value is likely to be either zero (no event cycles) or one (one event cycle). If the telemetry interval is longer, larger values are displayed when many event cycles are completed within one telemetry interval.
- ProgrammingCyclesCompleted—shows the number of programming cycles completed within the specified telemetry interval.

The telemetry time interval is configurable; the default value is 10 seconds. See Changing the Sample Interval.

RFID Device telemetry metrics let you monitor how long read cycles are taking, and keep track of how many read cycles have occurred in the specified time interval. Also, you can see how many tags each reader is reading. Telemetry information for each logical reader (antenna) is displayed.

RFID Device metrics include:

- readCycles—shows when read cycles occurred.
- readCycleTime—shows how much time each reader is taking for a read cycle.
- tagsInField—shows how many tags this logical reader (antenna) has read.
- writeCycles—shows when write cycles (programming cycles) occurred.
- writeCycleTime—shows how much time each reader or printer is taking for a write cycle.

For more information, see Monitoring Edge Servers and Monitoring Readers.

## Selecting a Server

The Metrics tab displays metrics available for a single Edge Server at a time. To select a different Edge Server, select the server from the Server drop-down list. The Server drop-down list displays all the Edge Servers configured in the Edge Server Administration Console.

## Understanding the Contents of the Metrics Tab

The Metrics tab displays a tree containing the following:

- Metric types
- Currently registered instances of the metric types
- Attributes of the listed registered instances

Table 5-1 describes the visual cues that help to identify items in the metrics tree.

Table 5-1 Visual Cues for the Metrics Tree
Visual Cue | Description
--- | ---
| An metric type with at least one registered instance
| A registered instance of the metric type
| An attribute of a registered metric instance

## Displaying Items in the Metrics tab

The tree shows the available runtime metric types, instances, and attributes for an Edge Server. Display items in the Metrics tab, as follows:

- To view the metrics from a different Edge Server, select the server from the Server drop-down list. (You can display metrics from only one Edge Server at a time.)
- To refresh the tree for the selected Edge Server, click the Reload button next to the Server drop-down list.
- To show all currently registered instances of a listed metric type, click the (Expand) button to the left of the type name.
- To show all attributes of a listed metric instance, click the (Expand) button to the left of the metric name.

## Displaying Details About Instances and Attributes in the Metrics Tab

You can display details about metric instances and attributes by placing the mouse pointer over items displayed in the Metrics tab:

- Point to an metric instance name to display the full object name of the instance.
- Point to an metric attribute name to display the type and description of the attribute.

For more information about displaying these kinds of details, see Displaying Tooltips for Controls, Views, Graphs, and Charts.

## Displaying Details About Metrics Charts and Graphs

You can display details about metrics charts and graphs displayed in the View panel by pointing the mouse pointer at objects in the panel:

- Point to a data point in a graph to display the time the data point was plotted and the sampled metric value at that time.
- Point to a chart legend to display the object instance name for each attribute listed in the legend.
- Point to a chart scrollbar to display the beginning date and time and the ending date and time for the visible interval. This tooltip also tells if this interval is the current interval.

For more information about displaying these details, see Displaying Tooltips for Controls, Views, Graphs, and Charts.