Manual

Model 391 User Guide Issue 2, December 2018
Studio Technologies, Inc. Page 17
Line Output
What is present on the line output con-
nection will depend on the configuration
settings associated with the active Model
391 operating mode. Some applications
will have no audio present on the line out-
put. Other configurations will have audio
from Dante receiver channel 1 or channel
2 present at all times on the line output. In
other cases audio will be present on the
line output only when a call signal is being
received.
Technical Notes
IP Address Assignment
By default the Model 391’s Ethernet inter-
face will attempt to automatically obtain an
IP address and associated settings using
DHCP (Dynamic Host Configuration Pro-
tocol). If a DHCP server is not detected an
IP address will automatically be assigned
using the link-local protocol. This proto-
col is known in the Microsoft® world as
Automatic Private IP Addressing (APIPA).
It is also sometimes referred to as auto-IP
(PIPPA). Link-local will randomly assign
a unique IP address in the IPv4 range of
169.254.1.0 to 169.254.254.255. In this
way multiple Dante-enabled devices can
be connected together and automatically
function, whether or not a DHCP server
is active on the LAN. Even two Dante-
enabled devices that are directly intercon-
nected using an RJ45 patch cord will,
in many cases, correctly acquire IP
addresses and be able to communicate
with each other.
An exception does arise when trying to
directly interconnect two Dante-enabled
devices that use Ultimo integrated circuits
to implement Dante. The Model 391 uses
Ultimo and, as such, a direct one-to-one
interconnection to another Ultimo-based
product is not supported. An Ethernet
switch linking the two units is required
to successfully interconnect two Ultimo-
based devices. The technical reason that
a switch is required relates to the need
for a slight latency (delay) in the data flow;
an Ethernet switch will provide this.
Using the Dante Controller software ap-
plication the Model 391’s IP address and
related network parameters can be set for
a fixed (static) configuration. While this
is a more involved process than simply
letting DHCP or link-local “do their thing,”
if fixed addressing is necessary then this
capability is available. But in this case it’s
highly recommended that every unit be
physically marked, e.g., directly using a
permanent marker or “console tape,” with
its specific static IP address. If knowledge
of a Model 391’s IP address has been
misplaced there is no reset button or
other method to easily restore the unit
to a default IP setting.
In the unfortunate event that a specific
Model 391’s IP address is “lost,” the
Address Resolution Protocol (ARP) net-
working command can be used to “probe”
devices on a network for this information.
For example, in Windows OS the arp –a
command can be used to display a list of
LAN information that includes MAC ad-
dresses and corresponding IP addresses.
The simplest means of identifying an
unknown IP address is to create a “mini”
LAN with a small PoE-enabled Ethernet
switch connecting a personal computer to
the Model 391. Then by using the appro-
priate ARP command the required “clues”
can be obtained.