Two types of fault inputs may
be monitored.
1) Dry contact closures where type may be
set via dip switch setting.
a.
Set S5-1 to “Off”
for normally open fault input.
(Closure=fault)
b.
Set S5-1 to “On”
for normally closed fault inputs. (Open =fault
2)
Supply current
Fault. The current being provided by the
controller, out to the amplifiers should operate
within a settable window. Should the
current fall outside this window, then a fault
may be declared.
Separate Fault type enables:
a.
Set S5-2 to “On” to
enable dry contact fault input monitoring.
b.
Set S5-2 to “Off”
to disable dry contact fault input monitoring
c.
Set S5-3 to “On” to
enable current monitoring faults
d.
Set S5-3 to “Off”
to disable current monitoring faults
Dry
Contact Fault Inputs:
These fault inputs are fed
into the controller through the rear chassis
D-Sub type (Soc) connector J3. Two pins
are allocated for each amplifier.
Note: The
FIG. 3
Normally open fault defined:
A normally open fault input
is defined by this document as a fault input
that is “normally open” in a no fault condition.
When the “normally open” fault input closes, a
fault is declared. A closure causes a
fault. (short across the two fault pins)
Normally closed fault defined:
A normally closed fault input
is defined by this document as a fault input
that is “normally closed” in a no fault
condition. When the “normally closed”
fault input opens, a fault is declared.
These two fault pins being open (no contact with
each other) constitutes a fault condition.
Current Monitoring Faults:
Setting Up Current
Monitoring:
When the amplifier is ON, it
should be drawing current from a supply inside
the controller. This current is monitored
in such a way, that should it deviate from a
specified window, a fault is declared.
Set Dip switch 5-3 to “ON”.
(Factory set to “On”)
This will instruct the DNL-5
to monitor the currents being drawn from the
amplifiers. This monitoring will affect
automatic function.
When an amplifier operates
outside its window for more than a few seconds,
a fault is declared. This fault will show
up on the front panel by the associated fault
led turning from green to a flashing red.
In order to set up an
amplifier, a minimal amount of adjustments must
be made. These adjustments (setting a
potentiometer) allows the DLN-5 to be used with
just about any amplifier. The adjustments
are necessary because different amplifiers draw
a different amount of current.
A current monitored fault is
declared when the current being monitored falls
outside the “window”. The “window” is
between 2.5V - DELTA V and 2.5V + DELTA V.
Please Note that the
amplifier currents are available on the computer
port, but these measurements mustn’t be used for
any fine measurement purposes. The A/D
converter used on the DNL-5 is an 8-bit device.
That means that each bit is worth 20 mV.
There is a 1:1 relationship between current and
voltage with this application, so each bit is
worth 20 mA of current. Therefore, the
measurements available on the computer interface
port are to be viewed as somewhat coarse numbers
only.
One nice feature of the DNL-4 is the ability of
the user to monitor the current being drawn from
an amplifier in real time using only a volt
meter. Each amplifier has a test point where a
volt meter may be connected. The voltage being
read may be interpreted as the current being
drawn by the amplifier. For instance, if the
user measures 0.240 V,
