Acromag, Inc. Tel: 248-295-0880
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Model SP33X-0700
4-Wire DC I/V Signal Splitter w/USB
Diagnostics Table…
Service & Repair Assistance
This unit contains solid-state components and requires no maintenance, except for
periodic cleaning and transmitter calibration (zero and full-scale) and verification.
Its enclosure is not meant to be opened for access and can be damaged easily if
snapped apart. It is highly recommended that a non-functioning transmitter be
returned to Acromag for repair or replacement. Acromag has automated test
equipment that thoroughly checks and calibrates the performance of each
transmitter, and can restore firmware. Please refer to Acromag’s Service Policy and
Warranty Bulletins, or contact Acromag for complete details on how to obtain
repair or replacement.
POSSIBLE CAUSE
POSSIBLE FIX
Output goes right to Over-Range (105%) or Under-
Range Limit…
This indicates that either the
input signal is out of range,
scaling is incorrect, or a sensor
lead has broken. It can also occur
due to contention between earth
ground at the PC USB port and
the input sensor.
Check the input signal and adjust it as
required to drive the output to within its
linear operating range. A fully upscale or
down-scale signal can be driven by a sensor
fault, such as an open/broken sensor lead.
Check the wiring of your input sensor. If
you are not isolating USB, check for a
ground loop between a grounded sensor
and earth ground of the PC USB port.
Cannot Calibrate Input Channel…
Is input wired properly?
Check that input is wired to ± input
terminals using correct polarity.
Changing Input Filter Setting Affects Input Calibration…
You may note a small shift in the
input reading when changing the
input filter setting.
An input should be calibrated at the desired
filter setting. For best results, set the input
filter as desired before calibrating the input.
Cannot Measure Input Voltage or Current…
Have you wired the input to the
correct terminals for the range
selection?
DC Current is input to TB1 (upper block),
while voltage is input to TB2 (lower block).
Make sure that you are wired to the proper
input per your signal type.
Output Noise Seems Excessive…
Scaled input or output range is
too small.
Scaling the input/output to very small spans
diminishes I/O resolution and signal to noise
ratio, potentially magnifying error. Every
halving of the nominal range reduces
resolution by 1-bit. Increase the I/O span.
An orange output fault LED is ON...
The corresponding current output
load is too large to drive it
accurately or is an open-circuit, or
the output driver has over-
heated.
Indicates the current output load is open
circuit or its load is too large to maintain
output accuracy (≤525Ω), or the IC die
temperature has exceeded 142°C (resets
upon cooling below 124°C). It may also
occur if the loop supply voltage is too low to
support the load.