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MBOX® 2016 DUAL OUTPUT HARDWARE MANUAL
CONNECTED DISPLAY DEVICES AND EDID
Overview
Without special hardware or software, a computer can only output video resolutions and frequencies that are supported
by the connected display equipment. Display devices communicate their possible input formats via EDID (Extended
Display Identification Data). The EDID data provides information on preferred formats and available alternate formats.
In order to provide some of the specialized outputs - for example, the various SDI signals - from the Dual I/O Module,
the computer must be told that it can output specific frequencies or resolutions. For this reason, the I/O Module
incorporates EDID management for both video outputs of the Mac Pro computer. The I/O Module always tells the
computer what frequencies and resolutions are possible; EDID from connected devices is never passed through directly
to the computer unless “captured” by the I/O Module (as will be covered later in this chapter).
IMPORTANT!
In order to output SDI, the I/O Module must be using one of its built-in EDID sets, and cannot be using
captured EDID.
The Mbox v4 software reads the current resolution and frequency of all connected displays, as this information is
provided by the OS. When Mbox v4 goes into Fullscreen mode it will
only use the resolution and frequency that the
display is currently set to. Older versions of the Mbox application attempted to change the resolution and frequency of
outputs when entering Fullscreen mode. At times this could lead to confusing situations where the desired resolution or
frequency were not applied, or where the display device could not display a picture based on the received format.
To eliminate these issues, Mbox v4 will not change the display into another format when going into Fullscreen mode.
The resolution and frequency of a display must be pre-set in the System Preferences > Displays preference pane
before entering Fullscreen mode.
When a display’s format is changed on the Displays pref pane, that new format will
update automatically in the display assignment menu for outputs in the Mbox application. (Refer to “Outputs Tab: Output
Configuration” on page 57 of the Mbox v4 User Manual)
When connecting the I/O Module’s video outputs to a display device, confirm that the display device’s desired resolution
and frequency appear and are selected in the Displays pref pane. If the desired resolution and frequency are not
available, an alternate EDID set must be selected or EDID data should be captured from the connected display device.
The EDID information for each of the computer’s outputs is shown in the Displays pref pane. Both outputs will show a
window similar to the illustration below. The header of each window will display the name of the EDID set (e.g. PRG-
MbE 60Hz) or the name of the captured EDID (e.g. Cinema HD Display as shown below).
