A Rivendell log is a sequence of one or more events to be executed by the system, arranged in chronological order. (This functionality is sometimes referred to as a 'playlist' in other automation systems). Several different types of events can be included in a log, along with parameters governing how and under what circumstances they will be executed.

Upon startup, RDLogEdit will show the current list of all logs on the system, as shown below. A number of important attributes of logs can be seen from this illustration, the first being the log name, with a summary status indicator next to it. The name is an alphanumeric label that is used as a unique 'handle' by the system to reference each log, and can be up to a maximum of 64 characters long. The status indicator is intended as a quick visual guide as to whether a particular log is ready for air () or not ().

Next comes the log's description. This is a freeform alphanumeric label that can be used to record any information that might be useful to have appear on the log list (e.g. This log for Sunday's show, don't modify!).

Next comes a column showing the owning service. Each log is owned by exactly one service, which determines under what circumstances the log can be played and where electronic log reconciliation (ELR) data resulting from log playouts is sent (See Services for an overview).

Next comes three status indicator columns (MUSIC, TRAFFIC and TRACKS) indicating the log's degree of readiness for air.

Icon/Status	Meaning
	indicates that the particular data element is required but currently missing.
	indicates an element is required and present.
	indicates that an element is not required.

Additionally, the TRACKS column contains a pair of numbers indicating how many completed voice tracks exist in the log versus how many total track markers exist (e.g. 30/72).

When all three of these status indicators show either or , the summary status indicator (at the beginning of the log's entry in the list) will show as a .

A indicator in any of these three fields will show a . (NOTE: because a log sports a does not indicate that the respective log cannot be played. It is merely a visual indicator to allow logs to be quickly “eyeballed” for completeness).

Next comes a pair of columns indicating the valid start date and end date for the log.

Finally, there is a column indicating the log's origin (i.e. the place, date and time it was originally created).

A report that lists the available logs on the system can be generated by touching the Log Report button.

A new log can be created by touching the Add button and entering a name, or an existing log inspected and modified by touching its entry on the log list and then touching the Edit button, resulting in the log being opened in the Edit Log dialog as shown below.

The Edit Log dialog consists of three parts: the top section, where much of the information shown on the log list can be inspected and modified; the middle section, which shows the list of events comprising the log, and the bottom section, where buttons for modifying and saving the log are located. Each event in a log can be one of several different types, indicated by the icon displayed at the start of the line as shown below:

Icon	Meaning
	Audio Cart
	Voice Track Audio Cart
	Macro Cart
	Note Marker
	Track Marker
	Chain Event
	Music Import Link
	Traffic Import Link

The following types of events can be incorporated into a Rivendell log:

The first, and usually most common type of log event is an audio cart. As the name implies, audio carts are Library entries that contain audio material intended for playout. Audio carts are covered in detail Audio Carts.

A macro cart is a cart from the Library that contains one or more system commands that can be used to cause the system to take various actions. Further details are available in Macro Carts and Macros.

A note marker is an entry in the log that contains text intended to be seen by operators and used as a guide or reminder (program coders sometimes refer to this sort of functionality as a remark or comment, as seen in the REM command used by BASIC programmers). Note markers belong to a class of log events known as meta events because (unlike carts, which exist in the Library independently of whether they are placed in a log or not), they have no independent existence outside of the specific log where they are placed. A note marker has absolutely no effect on the execution of a log other than to simply display some text at a specified point in a log, and as such can be useful as a mechanism for making notes or reminders to oneself or to others who may be executing the log.

A track marker is another meta event that is very similar in operation to note markers, with one key addition: track markers designate or “bookmark” a place in the log where a voice track is to be recorded. (The entire topic of voice tracks and tracking will be covered in detail in Chapter Eight). As with note markers, track markers have absolutely no effect on the execution of a log.

A third type of meta event is the chain event. Unlike markers, a chain event has a very definite effect when executed in a log: namely, causing a new log (whose name is specified as part of the event) to be loaded and executed. Chain events are often placed at the very end of a log, typically just before midnight so as to cause a new log to load for the next broadcast day.

An import link is a placeholder event that shows where events imported from the external music or traffic scheduling system will eventually go. This is covered in detail in RDLogManager.

Each event in a log has a transition type, shown in the TRANS column of the Edit Log dialog. The transition type determines what happens when one event in a log ends and the next starts. Three basic transition types can exist in a Rivendell log:

If an event has a PLAY transition, then it will begin playing when the previous event has finished. PLAY transitions are used when automatic event sequencing is desired with no audio overlap (such as when playing two voice-only announcements back-to-back).

SEGUE transitions are similar to PLAY transitions, with one key difference: if the finishing event contains segue data (either from the Library or from a custom transition programmed in the voice tracker), then the event will start before the prior event is finished, causing the two pieces of audio to overlap and mix together. SEGUE transitions can be a very powerful tool for creating a variety of special effects, particularly when used in conjunction with musical material.

As the name implies, STOP transitions cause execution of the log to be suspended prior to execution of the event. This is often the desired behavior in situations where the log playout needs to be synchronized to one or more external audio sources (such as remote satellite feeds), and is commonly used in conjunction with Hard Timed events (see below).

All Rivendell log events have an associated time type, which controls what effect (if any) the passage of time will have on the event. There are two basic time types: relative and hard. Additionally, the hard time type has several additional options that further modify its behavior.

The default time type for log events, a relative time type simply means that the event is assumed to have a start time of whenever the previous event ends (if it has a PLAY or SEGUE transition) or whenever it is started (if it has a STOP transition).

A hard time type causes the event to be executed or otherwise acted upon when the wall clock equals the time associated with the event. Hard times are a powerful feature that can be used to synchronize the log to various external events. An event can be assigned a hard time by clicking the Start at check box in the Edit Log Entry and filling in the desired time, and will show up with the letter 'T' appearing at the beginning of its listed time in the TIME column of the Edit Log dialog. An event which has been assigned a hard time can also be set to be a Post Point by checking the Make Post Point check box (the concept of post points is detailed RDAirPlay).

The specific action that is performed when the time matches is determined by the option parameters supplied as part of the event. Three basic actions are possible:

• Start the event immediately
• Cue to the event (“Make Next”)
• Wait up to N Seconds, then start the event

As implied by the name, if the event is set to start immediately, it will be started as soon as the hard time is reached. Any currently playing events in the log will be stopped immediately.

If set to 'Make Next', the event will be cued up to become the next event to be executed in the log, bypassing any intervening events in the log between the currently playing event and the hard timed one. Any currently playing events are unaffected.

Very similar to “start immediately”, with the difference that, if one or more events are currently playing, the log will wait up to the specified number of seconds before stopping them and starting the new event.

The cart number to use for an event can be specified by touching the Select Cart button in the Edit Log Entry dialog, which will open up the Select Cart dialog, as shown below. Alternatively, it is possible to simply enter the cart number in the Cart field if the number is already known. The Title and Artist information will be automatically supplied by the system from the cart's label.

Note marker and track marker events each take only a single parameter: a Comment text that will show up on the log entry. In the case of a chain event, the name of the log to chain to must be supplied in the Log Name field, or the Select button can be touched to bring up the Select Log dialog to allow a name to picked from a list of all those available. Note that meta events are assigned transition and time types just the same as cart events.

Existing events in a log can be cut, copied, pasted or rearranged by touching the appropriate buttons in the Edit Log dialog. In addition, touch the Delete button will cause the selected log event(s) to be removed from the log¹⁾.

Any changes made to a log can be saved by touching either the Save or OK buttons in the Edit Log dialog. The current log can be saved under a different name by touching the Save As button, while touching Cancel will abandon any changes made since the last save.

If a given event has a problem (such as referencing a cart that does not exist in the Library, or that is not enabled for play on the log's owning service) its entry will be highlighted either RED (indicating a missing/invalid cart) or FUCHSIA (indicating a cart without permission to run on the owning service). It's also possible to generate an exception report summarizing problem cart entries by touching the Check Log button.

Various Log reports can be generated by touching the Reports button on the Edit Log dialog and then selecting the desired report and touching the Generate button.

The following reports are available:

A chronological listing of all events in the log.

Example:

                                                     Rivendell Log Listing
Generated: 06/04/2017 - 00:53:16                        Log: Prod-0603-Backup                Description: Production log for 03/06/20
Service: Production          AutoRefresh Enabled: Yes   Start Date: [none]                   End Date: [none]

-Type-- -Time---- Trans -Cart- -Group---- -Length- -Title--------------------------- -Artist----------------------- -Source----- Line
Audio   H         SEGUE 060001 IDENTS          :21 On the Up Hungerford                                             RDLogManager    0
Audio    00:00:21 PLAY  060238 VOXSFX          :01 1-V2-TheNewsOnTheHour                                            RDLogManager    1
Audio    00:00:23 SEGUE 040026 BEDS            :28 Across-The-Globe-4-(30)           AudioNetwork                   RDLogManager    2
Audio    00:00:51 SEGUE 040025 BEDS           2:04 Across-The-Globe-2                AudioNetwork                   RDLogManager    3
Audio    00:02:55 SEGUE 090001 NEWSVOX        1:59 News Latest                       Sky News                       RDLogManager    4
Audio    00:04:54 PLAY  040026 BEDS            :28 Across-The-Globe-4-(30)           AudioNetwork                   RDLogManager    5
Audio    00:03:30 SEGUE 010056 MUSIC          3:31 Changes                           David Bowie                    Music           6
Audio    00:06:00 SEGUE 010142 MUSIC          3:24 Sexy and I Know It                LMFAO                          Music           7
Audio    00:09:00 SEGUE 010065 MUSIC          2:04 You Need Me, I Don't Need You     Ed Sheeran - You Need Me, I Do Music           8
Audio    00:12:00 SEGUE 010122 MUSIC          4:47 Samuel and Rosella                Lemon Demon                    Music           9
Audio    00:15:00 SEGUE 010092 MUSIC          3:32 It's Not Over Yet                 Klaxons                        Music          10
Audio    00:18:00 SEGUE 010242 MUSIC          3:28 What Am I Fighting For            UNKLEJAM                       Music          11
Audio    00:21:00 SEGUE 010154 MUSIC          3:34 Down Under                        Men at Work                    Music          12
Audio    00:24:00 SEGUE 010167 MUSIC          2:44 Won't You (Be There)              NERO                           Music          13
Audio    00:27:00 SEGUE 010052 MUSIC          3:06 Accidentally in Love              Counting Crows - Accidentally  Music          14
Audio    00:30:00 SEGUE 010252 MUSIC          3:24 Is There Anybody Out There        Bassheads                      Music          15
Audio    00:33:00 SEGUE 010161 MUSIC          3:43 Hysteria                          Muse - Hysteria [Absolution 20 Music          16
Audio    00:36:00 SEGUE 010020 MUSIC          4:32 Dixieland                         Biblecode Sundays - Dixieland  Music          17

[Truncated]

A list of missing/unplayable carts referenced in the log.

Example:

Rivendell Log Exception Report
Generated at: 06/04/2017 - 00:53:39
Log: Prod-0603-Backup
Effective Airdate: 06/03/2017

 09:21:00 - missing cart 010111
 14:15:00 - missing cart 010111
 15:12:00 - missing cart 010002
 19:51:00 - missing cart 010002

4 exceptions found.

The audio referenced by an audio event can be sampled in the Edit Log dialog by highlighting the desired event and then touching the play button. No attempt to evaluate the rotation logic of the event is made – the audio played is intended solely as a 'sample' to help identify the type of material.

Note the Play and Stop buttons at the bottom of the screen.