GENERAL DESCRIPTION
The Apollo Intelligent Strain Gage Meter
(IMS)
accepts low level signals
from a variety of bridge-type transducers, such as load cells, pressure
transducers, torque transducers, etc. User selectable low
(20 mV)
and high
(200 mV)
input ranges and a stable bridge excitation voltage, that is user
selectable to 5 V or 10 V
(60 mA max.)
, are provided. Internal resolution in
excess of 40,000 units allows detection and indication of the smallest signal
change. A two Hz, two pole, low-pass filter coupled with programmable
digital filtering can be tuned to match the characteristics of any process. A
digital tare
(re-zero)
operation can be performed at a touch of a button along
with recall of process peak and valley readings
(max/min)
. State-of-the-art
digital circuitry virtually eliminates errors due to drift. A full complement of
option packages is available to fulfill many process applications.
The indicator features a choice of two different scaling procedures which
greatly simplifies initial set-up. A full 6-digit display accommodates virtually
any process engineering unit. English-style display prompts and front panel
buttons aid the operator through set-up and operation. A front panel lock-out
menu protects set-up data and operation modes from unauthorized personnel.
Programmable remote input
“E1-CON”
pin can be utilized to control a variety
of functions, such as totalizing, alarm control, peak/valley readings, display
hold and tare operations. All set-up data is stored in E
2
PROM, which will hold
data for a minimum of 10 years without power.
As a standard feature, the integrator
(totalizer)
/linearizer can be used to
totalize or integrate signals up to a maximum display value of 999,999. It features
independent scaling and a low signal cut-out to suit a variety of signal integration
applications. Additionally, nine slopes and offsets can easily be programmed to
linearize transducers with non-linear outputs, such as square law devices.
Programmable remote input
“E2-CON”
pin is included and can be utilized to
control a variety of functions, such as totalizing, alarm control, peak/valley
readings, display hold or tare operations, simultaneously with
“E1-CON”
pin.
Peak/valley
(max/min)
reading memory, and a signal re-zeroing
(tare)
function
are included and they are easily recalled and controlled by either the front panel
or a remote input. All readings are retained at power-down.
Optional dual relays with parallel solid state outputs are fully programmable
to operate in a wide variety of modes to suit many control or alarm applications.
Optional 20 mA loop, bi-directional serial communications provides
computer and printer interfacing to extend the capabilities of the indicator.
More than one unit can be addressed in the loop with other RLC products
which have serial communications capabilities.
An optional 4 to 20 mA or 0 to 10 VDC re-transmitted analog output can be
scaled by the user to interface with a host of recorders, indicators and
controllers. The type of analog output is determined by the model ordered.
(See Ordering Information for available models). The indicator has several
built-in diagnostic functions to alert operators of most any malfunction.
Extensive testing of noise interference mechanisms and full burn-in makes
the indicator extremely reliable in industrial environments. The die-cast front
bezel meets NEMA 4/IP65 requirements for washdown applications. Plug-in
style terminal blocks simplify installation and wiring change-outs.
SAFETY SUMMARY
All safety related regulations, local codes and instructions that appear in
the manual or on equipment must be observed to ensure personal safety and to
prevent damage to either the instrument or equipment connected to it. If
equipment is used in a manner not specified by the manufacturer, the
protection provided by the equipment may be impaired.
Do not use this unit to directly command motors, valves, or other actuators
not equipped with safeguards. To do so, can be potentially harmful to persons
or equipment in the event of a fault to the unit.
THEORY OF OPERATION
The IMS employs a microprocessor to perform the A/D conversion on the
input signal via a voltage-to-frequency converter. It digitally scales the
result, corrects for meter drift which may be present and then displays the
result in a 6-digit display
(5 for input, 6 for totalizer)
. The inputs are filtered to
enhance the stability of the display. A non-volatile E
2
PROM memory device
provides permanent data retention for operating variables. The display
consists of drivers and 6-digit solid-state LEDs. The alarm option employs
opto-isolators to isolate the open collector devices from meter common.
Operating in parallel, the relays are type Form-C and are rated at 5 Amps. The
serial communication option features a built-in 20 mA current source and
complete opto-isolation. The analog option features a 12-bit DAC and
provides an output signal that is digitally scaled. The re-transmitted output is
isolated from meter common.
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