Model DT33x-0700
4-Wire DC I/V Dual Transmitter w/USB
Acromag, Inc. Tel: 248-295-0880
- 27 -
http://www.acromag.com
- 27 -
https://www.acromag.com
Diagnostics Table
…
POSSIBLE CAUSE
POSSIBLE FIX
Software Fails to Detect Transmitter…
Communication or power was
interrupted while USB was
connected and configuration
software running.
Close the current connection with the
software, then select and re-open the
transmitter for communication (or simply
exit the Configuration software and reboot
it).
For an input step, the output appears to make 2 steps to reach its final value…
For a step change in the input, the
A/D needs 2 input samples to
ramp up to its final level.
To step the input, it takes two samples for
the A/D to ramp up to its final output level,
evident when using a scope to examine the
output transition in response to an input
step change, which appears to make two
steps in its transition to its final level.
For Service & Repair:
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.
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 and adjust the input signal as
required to drive output within its linear
operating range. A fully upscale or down-
scale output can be driven by a sensor fault,
such as an open/broken sensor lead. Check
input 1 sensor wiring. If not isolating USB,
check for a ground loop between sensor &
earth ground of 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?
Each channel has two potential signal paths
at TB1 and TB3
—
have you wired your signal
to the proper input per your signal type.
Output Noise Seems Excessive
…
Scaled input or output range is
too small.
Scaling the I/O to very small spans will
diminish resolution and signal to noise ratio,
potentially magnifying error. Every halving
of the nominal range reduces resolution by
1-bit. Increase your 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 load is open-circuit or
too large to maintain its output accurately
(
≥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.
