Acromag DT236-0600, Руководство пользователя, Страница: 35 / 40

Model DT23x-0600 Dual Two-Wire DC I/V Input Transmitters
Acromag, Inc. Tel: 248-295-0880 - 35 -
http://www.acromag.com
- 35 - https://www.acromag.com
Output
This unit has three operating
modes: dual transmitter, single
channel 1 transmitter, and CH1
signal splitter. Channel 1 loop
power must be present in any
mode.
Output Range: 3.5-24mA DC possible, 4-20mA nominal. Selecting Namur NE 43
clamp limits will provide a linear under-range down to ~3.7mA, and over-range up to
~20.7mA. Alternatively, you may set your own limits in a 3.5mA to 24mA range.
Output current is linear with respect to the DC input current or voltage applied at the
input terminals of the model (DT236 models optionally support AC current input at
input path A when wired for use with Acromag AC Current Sensor 5020-350).
Output Accuracy: Accuracy is typically better than

0.05% of span (

0.1% Max) for
nominal input ranges. Relative accuracy varies with calibrated input and output
span, and scaling. Accuracy includes the combined effects of repeatability, terminal
point conformity, and linearization, but does not include sensor error.
Output Ripple/Noise: Less than

0.1% of output span.
Note – High Speed Acquisition: Additional filtering at the load is recommended for
sensitive applications with high-speed acquisition rates. For excessive 60Hz supply
ripple, a 1uF or larger capacitor is recommended at the load. High frequency noise
may be reduced or eliminated by placing a 0.1uF or 0.01uF capacitor directly across
the load (this can also raise RF immunity).
Output Ambient Temperature Effect: Net effect of zero and span drift over
temperature is better than ±0.008% of span per

C (

80ppm/

C) over the full
ambient temperature range for reference test conditions (see Input Specifications).
Output DAC Resolution: Each output includes a 16-bit current DAC (Texas
Instruments DAC161S997RGH) with current set to 24mA*COUNT/65536 (see Table
3). Its 4-20mA output will yield an output resolution of 54613-10923, or 1 part in
43690. Linear range limits are programmable or set to Namur limits near ~3.7mA
(low) & ~20.7mA (upper), allowing you to discern an upscale or downscale lead break
condition from the linear operating range. The effective I/O resolution of this
transmitter will be the lowest of either the input, normalization, or the output.
Table 3: Output DAC Current Level & Digital DAC Count
I-LOOP = 24mA*COUNT/65536
COUNT = 65536*I-LOOP/24mA
3.7mA 10103
4.0mA 10923
12mA 32768
20mA 54613
20.7mA 56525
23.9996mA 65535
Output Response Time: The typical time per input filter setting measured for the
output to reach 98% of its transition with a step change in the input signal while
driving output current to a 250

load in series with a 24V loop supply.
RESPONSE TIME TO 98% OF TRANSITION (TYPICAL)
FILTER DT236 DT237 DT238
NONE 31ms 136ms 39ms
LOW 51ms 147ms 62ms
MEDIUM 152ms 317ms 195ms
HIGH 1100ms 1109ms 1109ms