Manual

Issue 1, September 2015 Model 43D User Guide
Page 16 Studio Technologies, Inc.
the two DC status LEDs on the front panel
will steadily light. So under normal condi-
tions where the performance is as expected
both LEDs will be lit. If 24 volts DC or less is
present on either powered IFB output a low-
voltage condition is detected. This would
typically be caused by connected devices
drawing too much current (more than 120
milliamperes) or a full short circuit being
present. If an under-voltage condition is
present for a continuous 1-second period a
fault condition is recognized. The associated
DC status LED will indicate this condition by
flashing on and off. In addition, the output
voltage on the powered IFB output will auto-
matically shut down to an essentially off con-
dition. This protects the IFB power source
and allows any connected devices to power
down. A 5-second “cool-down” period will
then take place, after which the IFB output
voltage will again become active. As soon
as the IFB output is enabled for three sec-
onds normal output voltage monitoring will
again take place. In summary, a continuous
short circuit or over-current condition pre-
sented to a powered IFB output will result in
a continuous 4-seconds-on/ 5-seconds-off
cycle. It’s important to note that during the
5-seconds-off period no voltage monitoring
takes places. Removing the fault condition
will not result in the IFB output voltage im-
mediately turning on again; the 5-second
shut-down period must first elapse.
Line-Level IFB Outputs
No special precautions are necessary when
using the line-level IFB outputs. The IFB line
output circuitry is protected from damage
should a moderate DC voltage be acciden-
tally connected. For example, no damage
will occur if a Model 43D’s powered IFB
output (28 volts DC) be accidentally con-
nected to one of the IFB line outputs. This
protection would also be effective should
a party-line intercom circuit or microphone
P48 phantom power signal be accidentally
connected to an IFB line output.
Users unfamiliar with the Model 43D may
not understand that the nominal level of the
line outputs is –10 dBu. This may lead them
to assume that there is an issue. But opera-
tionally there should rarely be a problem.
Should a higher nominal level be required
it can typically be “made up” in the con-
nected device(s).
USB Interface
A USB type A connector and associated
status LED is located on the back panel of
the Model 43D. This data interface is used
only for updating the unit’s application firm-
ware. No audio data of any kind will pass
through it. For details please refer to the
Technical Notes section of this guide.
Technical Notes
IP Address Assignment
By default the Model 43D’s Ethernet inter-
face will attempt to obtain an IP address
and associated network settings using the
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 assign an IP ad-
dress in the IPv4 range of 169.254.0.1
to 169.254.255.254. In this way multiple
Dante-enabled devices can be connected
together and automatically function, wheth-
er or not a DHCP server is active on the