Working With AV-Sync Hub

The AV-Sync Hub plays a vital role in today's complex play out scenarios. It makes it possible to coordinate the activity of multiple iterations of AV-Playback running on separate computers and do it all simultaneously. Another important aspect is that it also coordinates activity between a primary workstation and for most events, the required backup unit.

The hub is just that, a network connection point where play units can either deliver or receive broadcasted commands. However, it goes further than that by actively measuring network latencies and then uses that information to regulate, individually, the timing at which commands are received by each unit.  This technique works well in getting all units to work in a tight formation with one another.
Before we continue here are some things you first need to consider:
1) To better understand topics discussed here you should first read up on Workstation Roles & Networking Ground Rules.
2)  Review the control outline of the AV-Sync Hub.
3) Only one hub can be active on the network at any one time.
4) It is not necessary for this program to be running if all you want to do is use workstations in a neutral standalone fashion.
5) However, If also employing our MCS5 or 6 control surfaces. It will be required that the hub is used and launched by either ensuring the “Auto Launch Hub” property is checked or manually launching it before AV-Playback.   
6) It is assumed that the hub would run on the primary workstation given the use of the auto start feature but If desired a hub can reside on its own computer and remain safe from possible shutdowns, ensuring communications remain open with back up units. Keep in mind that run on another computer and you using a control surface. The controller will need the same computer as the hub.
How to Launch:
1)  Ensure that “Auto Launch Hub” option contained in AV-Playback’s ”Launch Control” is checked. When checked, every time AV-Playback is started, and you load its first playlist file, the hub will start.
     Remember only one workstation within a network can run the hub so you will not want the box checked on any of the other workstations.
2)  From AVP’s main menu click on “Utilities || Launch AV-Sync Hub
3)  From Windows Start menu go to AV-Playback_V2 and click to reveal all available shortcuts. Now click the “AV-Sync Hub” link.
Why a unique workstation name and index is important?
Technically it is having a unique index number that is most important. The name is merely to make it easier for you to distinguish between different workstations. Index, however, is what the hub uses in coordination with the stations IP to cross-reference them internally. There can never be two workstations on the same network with the same index number. This is so important that the hub will automatically force a new index number assignment to any workstation that newly connects and carries an index number already being used. You will know if it happens because this message will appear on the offending workstation:
As a good rule of thumb, for you to think of the designated primary as index 1, the backup as index 2 and all other can just be any number other than 1 or 2.
It is also good practice to already have a correct indexing scheme laid out before launching the hub. If the hub is already running and you launch a copy of AV-Playback, be sure to check its index in the Launch Control and make sure it will not conflict with others when you finally launch a playlist.
Delay Setting:
The delay setting can be used to delay activation of a received “Take” command from the primary. Generally, this is only used on the backup unit but can be applied to any other including the primary.     
How to link up to the hub:
Since much of programs other features are already described in the control outline we will focus just on how to connect a play unit to the hub.
Once the hub and all copies of AV-Playback are up and running you will note that each AVP node is represented in the hub’s workstation list.
We will get back to that but now let get familiar with the link button which appears on each playlist unit control window.
This button has three states-
Anytime there is no active AV-Sync Hub detected on the network this button will be disabled. Clicking it will have no effect.
Here a hub has been detected but the play unit is not currently linked to it and will not receive any broadcasted commands. Clicking it will initiate a link with the hub. 
Now we are currently linked to the hub and if you are working on the primary workstation all Program only transport commands will be broadcasted to all other workstation that is currently linked to the hub.   
Coming back to the workstation list you will find these three columns.
True they are an indication of its current state but they are also buttons that you can click. If you click on the one in the Linked column it will force toggle the link state of that workstation.
The Primary indicates of course which unit is the primary, but you click on another one to force the primary designation onto it.
The Backup column is discussed in another tutorial.
Commands that are passed from the Primary to all subordinates are as follows:
Selected Clip ID (NOTE: It refers to whatever appears in the primary's playlist clip ID column. If no match is found on a remote, the command is ignored.)
Fast Forward
60/30/20/10 Out
Scrub Position
Temp Hold
Temp Loop
NOTE: In the case of a backup subordinate there are a number of commands that are passed as well. We outline those in How To Setup Backup Workstation.