Media Control Protocol for ew G4 series

TI 1254 v1.0 - ew G4 | 7/37
Technical information
Media control protocol description
Response to get requests
When receiving a positive response the requested data will be transmitted to the media control.
If the command instruction is incorrect, the appropriate error message will be sent to the media
control.
Relative change
Some parameters can be incremented or decremented regarding to their current values. This is
indicated by adding a ‚#‘ before the parameter‘s value.
For example the instruction
Squelch #1<CR>
increments Squelch by one stepsize. If the Squelch value has been +11 before, it will be set to +13 as
Squelch can only be set in multiples of 2. Following instruction decrements Squelch by 2 steps:
Squelch #-2<CR>
assuming the previous Squelch value was +11 the new value is +7.
Monitoring of UDP/IP connection
In order to detect a UDP/IP disconnection a timeout mechanism is established in this protocol. The
media control has to send this timeout to Sennheiser devices to confirm that media control device
is still present. This timeout is passed by using the ‚Push‘ command. How to use this command is
described below in more detail.
Different ways to update the media control
There are different ways how Sennheiser devices can pass information to media control.
One way is that a set of attributes is sent periodically to media control. The cycle time can be
adjusted by a command. All attributes are sent out in one go. These attributes are called ‚Cyclic at-
tributes‘. It is also possible to disable the transmission of the cyclic attributes (see details of “Push“
command).
Another way to pass Cyclic attributes is to send them asynchronously due to a change of any warn-
ing. This can be adjusted via the Push command.
For an EM it is also possible to send Cyclic attributes asynchronously when a change of transmit-
ter‘s attributes is detected, for instance when the state of the pilot signal has changed. It can also
be adjusted via the “Push“ command.
Another way of passing information to the media control is that attributes of Sennheiser devices are
only sent if a change happened to this attribute. It is also possible to disable this behaviour for all
attributes together. But it is not possible to disable this mechanism only for one dedicated attri-
bute (see details of “Push“ command). The attributes which are only sent if a change happened are
called “Configuration attributes“.