Studio Technologies 42A 2013 - Manual (Page 18)

Issue 2, December 2013 Model 42A User Guide
Page 18 Studio Technologies, Inc.
one or both of the IFB output’s XLR con-
nectors. Another cause can be due to
problems with the IFB user devices. Either
a defective user device can be draw-
ing too much current or too many user
devices end up being connected to the
same IFB output. Troubleshooting an IFB
output circuit problem should prove quick
and easy. Begin by disconnecting the IFB
user devices. Observe the status LED and
see if the problem has gone away. If not,
review the interconnecting cables and find
the fault condition. Within ten seconds of
the problem being “cleared” the status
LED will stop flashing.
Determining the actual IFB output current
draw won’t often be required but can be
useful in a tough troubleshooting situa-
tion. This measurement can be performed
using any good-quality digital multimeter.
Begin by setting the meter to measure
DC current. Then place the meter leads in
series with the pin 2 lead of the XLR con-
nector associated with the IFB output to
be tested. The easiest way to measure
the pin 2 current is to create a simple
adapter cable using one female and one
male 3-pin XLR connector. Connect pin 1
on both connectors together. Connect pin
3 on both connectors together. Connect
separate wires to the pin 2 leads on both
connectors. Then connect the meter leads
to these two wires. The meter will indicate
the DC current being drawn while normal
operation of the connected device(s) takes
place. Be certain to connect the maximum
number of devices that might be pow-
ered by the IFB output. That is, measure
the worst-case condition and ensure that
the load is within the maximum 220 mil-
liamperes output. If possible, leaving a
5- or 10-percent reserve margin is a good
practice.
Technical Notes
Software Version Display
A special Model 42A power-up sequence
allows the unit’s software version number
to be displayed. This is useful when work-
ing with factory personnel on application
support and troubleshooting situations.
The five LEDs associated with the level
meter for pin 2 are used to display the
major release number with a range of 1
through 5. The five LEDs associated with
the level meter for pin 3 are used to dis-
play the release sub-number which ranges
from 1 through 5. Refer to Figure 9 for a
detailed view of the LEDs and the cor-
responding software version numbering
scheme.
To display the Model 42A’s software
version is very simple. From the pow-
ered-down state, press and hold the
IFB channel Circuit Select button. While
continuing to press the button, apply
AC mains power to the unit. The normal
power-up sequence will take place and
then, instead of one status LED being lit,
one LED in the Pin 2 column and one LED
in the Pin 3 column will light. These two
LEDs represent the unit’s current software
version. The software version number will
Figure 9. Detail of front panel showing the status
LEDs that display software version. In this example,
the software version is 2.1.