Layout Basics


The easiest way to introduce the "flow" of the program is to look at each window in turn. Before getting into the details of each window, here are some general layout patterns. Nearly all windows use the following layout: a toolbar (row of buttons) across the top; a set of tabs along the bottom; between the two you'll see either a table or a list.


The subpanel is a list of properties arranged as a two-column table. Each row in this table is a descriptive label on the left and some form of edit box on the right. Related rows are grouped into sections. You can navigate from one property to the next using the up/down arrows. Some properties are display only and therefore not editable. The Options tab on the main window follows this layout - as do the Info tabs found on numerous other windows.


Other windows will display a grid. You'll see a colum header displaying the name of each column. Flowing underneath the columns are the grid cells. Scroll bars may appear if rows are too wide for the window's width or there are more rows than can be displayed. Clicking on a cell makes that cell the current cell. The row will be highlighted and the cell will have a rectangle drawn around it. Navigate across cells using the up/down/left/right arrow keys. Most grids are editable. To prevent accidentally editing or erasing data, the cells are displayed as readonly. Clicking the Edit tool button (the handwriting icon) or pressing F2 key will place the grid in edit mode. While in edit mode, you can navigate between characters within a cell using the left/right arrow keys. When the cursor has advanced to the right most character in the active cell, pressing the right arrow key will advance to the next cell. If you're at the right-most cell of the current row, you will advance to first cell of the next row. You can exit edit mode by pressing the F2 key or clicking on the Edit tool. In other words, the F2 key and Edit button toggle edit mode between on and off.

Editing the contents of a cell does not make the change take place immediately. The actual change occurs when you navigate away from the cell or press the Apply tool button above. If you've accidentally edited a cell, you can recover the previous contents by pressing the Escape key. This also takes the grid out of Edit mode. There is no undo / redo mechanism. Once you've made a change, that's it.

Most grids will have tool buttons for Add, Delete, and Clone. The Add button will create a new grid item; the item being whatever sort of data is displayed in the grid. For example, the Add button on a grid of channels, would add a new blank channel. The Delete button will delete rows you've highlighted. You can highlight more than one row by holding the control key while clicking on each row. You can also use the shift key with the up/down arrow keys to highlight consecutive rows. A confirmation box will appear when you attempt to delete something. The Clone button creates a copy of the highlighted row.

Grid Multiselect

You can select multiple items and edit them all at once as follows. In the grid, select each item by highlighting it (use arrow keys or mouse) while holding down the control key. You'll end up with multiple rows highlighted. Click the Inspect toolbar (the magnifying glass icon). A popup window will appear allowing you to edit the items in aggregate. Set colors, priority, etc. all the same in one pass.

Main Program Window

The main program window appears when you start the program. If you close this window, the whole program exits. Close any other window and the program hums along quietly in the background.

The main window hosts a short set of tabs. The tabs are listed below.

Click on the Options tab to configure things that effect the look, feel, and sound of the entire program. Most options involving color come in pairs - a foreground and a background. For example, you can set the caption text to black on white, white on black or any other color. Be sure to pick colors that contrast. Black letters on a black background aren't readable. You can edit the color values by typing in the red, green and blue values or click the drop down arrow to pick from a palette of colors. You have your choice of display formatting for each protocol. The program will display group IDs, user IDs, and channel numbers in hexadecimal, decimal, or some proprietary format like AFS or Motorola. FWIW, system IDs are always displayed in hexadecimal.

The receivers tab lists all known configured receivers. The most common configuration is one receiver. However, know that you can have more than one; lots more.

The systems tab lists all previously logged systems. These are systems you've monitored before.

The archive tab lists current and previous revisions of your data. Each time you exit the program, a new revision is saved. Use the archive tab to manage these past revisions. You can roll back to a previous revision if you've made a drastic mistake. There's a save button to force the program to save all data (creating a new revision) without exiting.

The tri-color ABC tool button on the main program window manages your sets of color words.

Receiver Window

To see live activity, you'll need at least one receiver configured. The receiver window is where that work takes place. Read this explanation of the different classes and roles of receivers for decoding and voice following.

A signal receiver (either a signal class receiver or a both/inline receiver operating in the role of signal receiver) window displays health of the currently decoded signal. For signal role receivers with discriminator audio, an oscilloscope tab displays the live waveform.

A voice receiver (a control receiver or a both/inline receiver operating in the role of a voice receiver) window displays the source, target, and frequency of the currently followed voice call (if any).

Clicking the Site button on the receiver window takes you to the site window - if such a site is currently being monitored.

When a new signal is acquired, the decoder takes some time to gather three basic parameters: system ID, site number, and active control channel. Under poor signal conditions it may take a while to gather all three. Even under optimal decoding conditions, some systems broadcast these parameters so infrequently that it may take minutes to gather. However, once gathered, you'll see this next window pop up automatically.

Site Window

This is the only window that pops up when a new signal is acquired. There's a health meter in the top left. The site label appears as the window caption. Use the Info tab to see site statistics (total number of channels, active control channl), edit label, or enable site event logging. The channels tab lists all channels. The Call History tab is a split view of active calls (top) and event history (bottom). The Calls panel shows who is talking (source) to whom (audience). Double click a source cell to see the user as a separate pop-up window. Double click a target cell to see the talkgroup (or user for a direct unit-to-unit call) as a separate pop-up window. The SVC column describes the call type.

The History panel permits scrolling back through up to roughly four hours of traffic. Each event has a source, a target, and some sort of action. A quick synopsis of some events:

Common events types are:

Not all trunking formats support all event types. For example P25 provides login/out messages (unit registrations) while login status is inferred through joins and leaves for EDACS and Motorola.

The Peers tab, when present, displays a list of adjacent sites for networked systems. This can be very helpful for disambiguating two adjacent EDACS sites on the same network. They will mutually announce each other as peers. This tab is also useful for spotting Motorola Omnilink systems. If at least one neighbor site has a different system ID, you're looking at Omnilink.

The Bandplan tab displays the bandplan for Motorola and MPT1327. Each entry in the band plan will map a range of channel numbers (low and high) to a range of frequencies. The formula used is

f = step * (lcn - low) + base

Step (spacing) is in kilohertz. Base frequency is in Megahertz.

EDACS and LTR do not use bandplans. P25 systems announce the bandplan over the control channel (usually don't need to fuss with them).

When a new site window appears, you will see the control channel in red (color default). If the audience label displays "Frequency needed!", please type in the control channel frequency. For some inline and "both" receivers, the program can retrieve the frequency from the radio. In other cases, you'll need to enter it manually. This is particularly true when using a "dumb" signal only discriminator tapped radio when monitor EDACS, LTR or Motorola.

Knowing the control channel frequency aids the program in the following ways. EDACS and LTR have no system identity. There is no "system ID" that can be used to distinguish different systems. However, the control channel number, site number, and frequency are sufficiently unique to distinguish nearby systems. Example: three EDACS systems in Dallas, Texas - all appear as Site 01 with control channel 01. The only way to differentiate the three is by frequency.

Motorola decoding also benefits when monitoring a new site for the first time because it helps the decoder to distinguish between the different flavors of Motorola trunking. The messaging for 800/900 Mhz systems is very different from UHF/VHF systems.

For Motorola sites, there's a band wizard tool button (calculator icon). Use this for 800/900 Mhz trunking only. For VHF and UHF sites, you'll have to edit the band plan directly.

Clicking the Home button on the site window toolbar takes you to the System window.

Clicking the receiver button on the site window takes you to the receiver window - if that site is currently being monitored.

Sytem Window

Use the Info tab on this window to see system stats (total number of groups, users, sites), or edit label and notes. You'll find the system's list of talkgroups on the Groups tab. The list of users is on the Users tab. There is also a Channels tab that lists all channels "flattened" across all sites. This view is useful for spotting duplicate or erroneous channel entries. The Patches tab displays a list of past and present group patches. The Last Seen column indicates whether a specific patch is still active.

Clicking the Home button on the system window toolbar takes you to the main program window.

Talkgroup Window

Use this window to see hit counts, first/last seen timestamps, event history. Edit label, notes, color, listening options, and annunciation options. The History tab displays the event history for the group. All recent calls, affiliations, patches, and user rejects involving the talkgroup appear here.

Clicking the Home button on the group window toolbar takes you to the system window.

User Window

Use this window to see hit counts, first/last seen timestamps on the Info tab. Edit label, notes, color, listening options, and annunciation options. The History tab displays the event history for the user. All recent logins, calls, affiliations, pages, and rejects involving that user appear here.

Clicking the Home button on the user window toolbar takes you to the system window.

Channel Window

Use this window to see hit counts, first/last seen timestamps. Edit frequency, label, and color. The confirmed checkbox indicates a confirmed channel number/frequency pair. When you manually edit a frequency, this checkbox is set for you to prevent a download or bandplan from over-writing it with different data. The Control checkbox denotes a control channel.

Clicking the Home button on the channel window toolbar takes you to the site window.


Site numbers are displayed in a hypenated format. With decimal mode selected, site numbers appear as rrr-sss where "rrr" is the RFSS and "sss" is the three digit site number. You need both to uniquely identify a P25 site. RFSS stands for RF subsystem number (range of 0 to 255) which is used to group sites. The site number can also range from 0 to 255.

Channel numbers are displayed in a hypenated format. With decimal mode selected, channel numbers appear as ii-ccc where "ii" is the two digit identifier and "ccc" is the three digit channel number. You need both to uniquely identify a P25 channel. The identifier is an index into a table of up to sixteen entries in the system's band plan. The index selects the appropriate base/offset/and step to calculate frequency from the channel number.


Talkgroups are displayed as 16 bit numbers. They're actually 12 bit numbers. The value you see is the actual talkgroup multiplied by 16. Talkgroups are displayed this way for historical reasons related to compatibility across Type I systems. The format makes spotting the relationship between a Type I radio ID and Type I talkgroup very easy.

Type I talkgroups are grouped into any one of eight blocks. The number of radios addressed by a single Type I talkgroup is determined by a sizecode. You can edit the sizecode on the system's info tab. Type II systems have all eight sizecodes set to "2" to indicate a Type II bank.


LTR talkgroups use a hyphenated format of a-hh-ggg where "a" is the area digit (0 or 1), "hh" is a two digit home channel number (1 to 20) and "ggg" is a three digit group number (1 to 255). You need all three components to uniquely identify a talkgroup on an LTR system. There are no radio IDs on LTR.

© Copyright 2008-2011 Rick Parrish