When using AES-3 I/O, the UPMAX ISC can be referenced to either the AES-3 clock (using the SRCs in the
SDI path) or to the SDI clock (using the SRCs in the AES-3 path.
When using an AES-3 source without an accompanying reference, the UPMAX ISC’s 48kHz internal clock
can be used as the system reference if necessary, providing the SRC on the AES-3 input is enabled.
Whenever AES67 audio is used either on the input, the output, or both, the UPMAX ISC must slave to an
externally-generated PTP clock as it cannot generate its own PTP reference.
NOTE: The UPMAX ISC is set to operate in slave mode by default. There are controls in the Sync/
QoS sub-menu of the System menu to change this should the ability to operate as a clock master
be introduced in future software versions, but only Slave Only mode is currently supported.
Setting Clock Reference
Click on the Clock menu (5-9A). Use the dropdown menus to choose a Primary Reference Clock and a
Secondary Reference Clock (5-9C) and, if needed, a VRef clock source (5-9E).
A status field (5-9D) is provided for the selected Primary and Secondary Reference Clocks to the right of
the dropdown menu. The absence or presence of a signal for each input type along with the format,
resolution, and frame rate for incoming SDI signals is shown in the Input Status section (5-9B).
Figure 5-9 - Clock reference
GPI/O
