
Model DT23x-0600
Dual Two-Wire DC I/V Input Transmitters
Acromag, Inc. Tel: 248-295-0880
- 28 -
http://www.acromag.com
- 28 -
https://www.acromag.com
Diagnostics Table
…
Output goes above Over-Range (20.7mA), or below Under-Range Limit (3.7mA)...
If you have selected Namur
compliant output limits, the input
signal has gone outside of its
linear operating range from
3.7mA to 20.7mA, indicating a
fault condition of an open sensor
or broken sensor lead. It might
also occur due to contention
between earth ground at a non-
isolated PC USB port and input 1
sensor, or it may indicate failed
communication with the output
DAC (a firmware problem).
Check the input signal with respect to its
range and reduce or increase it as required
to drive the output current within its linear
operating range. A fully upscale or down-
scale signal can be driven by a sensor fault,
such as an open or broken sensor lead, a
ground fault with the input 1 sensor, or a
DAC communication error. 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.
Output holds last value when I connect USB…
Unit is awaiting initialization via
its configuration software used to
set it up, configure it, and
calibrate it.
Boot the configuration software to regain
operation. The USB port is intended for set
up and configuration of the module and a
unit should not be left connected to USB
without also executing its USB software.
Output Fault (FLT) LED blinks...
The corresponding output loop
voltage is too low to support the
loop load current, or the load
resistance is too high for the loop
supply voltage level. Note this
LED will blink one time if loop
power is turned off.
Check the corresponding output loop
voltage level and wiring. Verify your output
load resistance is less than R=(Vs-7)/0.02x.
Note that an isolated 2-wire output is earth
grounded at the Vs supply minus lead (load
minus), not the transmitter output.
Service & Repair Assistance
This unit contains solid-state components and requires no maintenance, except for
periodic cleaning and transmitter configuration parameter (zero and full-scale)
verification. The enclosure is not meant to be opened for access and can be
damaged easily if snapped apart. Thus, 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 the
Acromag Service Policy and Warranty Bulletin, or you may contact Acromag for
complete details on how to obtain repair or replacement.