MODEL 070M69 COMPUTATIONAL SIGNAL CONDITIONER MODULE
4
Four Difference Outputs that are each generated
from a set of two input channel signals. These
outputs
are labeled as ∆V1, ∆V2, ∆V3, and ∆V4
and they are mathematically equal to the following:
∆V1 = (+V1) – (-V1)
∆V2 = (+V2) – (-V2)
∆V3 = (+V3) – (-V3)
∆V4 = (+V4) – (-V4)
The fifth Summed Output is
labeled as Σ∆V and it
is generated from the four Difference Outputs and
a gain function. The equation for this output is as
follows:
Σ∆V = Gain*(∆V1 + ∆V2 + ∆V3 + ∆V4)
The gain switch allows for gain values of x0.1, x1,
or x10 in the equation above.
This computational signal conditioner is used to get
moment measurements in Force Limited Vibration
Testing.
This unit can also be used to just sum four input
channels by applying signals to the +Vx channels
only, leaving the
–Vx channels open. This would
result in the following Summed Output equation:
Σ∆V = Gain*((+V1)+(+V2)+(+V3)+(+V4))
Eight red LED fault monitors, one per channel, are
located on the front panel to provide the user a
means to check circuit continuity and operation.
Input faults, short or open, are indicated by the fault
LED being solid red.
Additionally, one yellow LED is located in the upper
right-hand corner of the front panel. This is the
Overload LED and it is on whenever any input, any
Difference Output, or the Summed Output exceed
10 Volts. This LED will remain on for as long as
one of these signals is above 10 Volts.
4.0 Operation
The Model 070M69 is designed to fit into the PCB
Modular Signal Conditioning System. It may be
used in any size chassis in combination with any
other modular series models. For further
information on the PCB Modular System, consult
the PCB Modular Signal Conditioning System sales
sheet.
The Model 070M69 can be powered from the
441A101 AC Power Module or the 441A102 DC
Power Module. Additionally it can be used in the
441A38 chassis that includes a built in AC Power
Module.
Please note that use of the 070M69 module with
the 441A102 DC Power Module will cause an
increase in the ICP® Excitation Voltage and
Current supplied to the sensors. This is due to the
higher 30 VDC Supply Voltage of this power
module compared to the other power sources. The
higher ICP® Excitation Voltage and Current will not
have any adverse affects on the operation of this
unit or the sensors attached to it. Please see the
specification sheet for more details.
4.1 Grounding
Indiscriminate grounding of instruments can
introduce ground loop interference. To prevent this,
it is necessary to insure that the signal ground lines
of the 070M69 and other instruments used with this
unit are grounded at one point only in the
measurement system.
If an instrument with a mains socket chassis
terminal is used in the measurement system,
check that a) that only one of the instruments has
its signal ground connected via the chassis to
mains ground, (b) that the housing of the
transducer is isolated from grounded measurement
sources.
If the measurement set-up is mounted in a metal
instrumentation rack, ensure that only one of the
instruments has its signal ground connected to the
chassis (and chassis connected to mains ground if
the unit has a mains socket chassis terminal).
5.0 Maintenance and Repair
No maintenance is required for this modular unit,
other than wiping the exterior of the enclosure with
a soft cloth when dusty. If you have trouble with
your particular unit, contact the factory for
assistance. Because of the sophisticated nature of
PCB
instrumentation,
field
repair
is
not
recommended.
Any field repairs on this unit will
