Model DT33x-0700
4-Wire DC I/V Dual Transmitter w/USB
Acromag, Inc. Tel: 248-295-0880
- 32 -
http://www.acromag.com
- 32 -
https://www.acromag.com
Input...continued
Input Resolution:
Input analog to digital conversion divides the input signal range
into parts calculated by subtracting endpoint A/D counts computed via the
expression (Vin*Gain/1.25) * 32768+32768. Vin is the voltage after the input divider
and gain is applied to the signal (see Table 1). The input divider is different for input
paths A & B. Ranges that share the same gain are calibrated by linearly extrapolating
from their nominal input range calibration. For simplification, raw A/D counts
indicated in Table 1 are normalized to ±25000/15.5 bits for
100% (bipolar ranges), or
0-25000/14.5 bits for 0-100% (unipolar ranges), and the effective input resolution of
a range will be the lesser of the raw resolution indicated in Table 1 or its normalized
resolution. The effective resolution of an I/O conversion will be the lowest resolution
of the A/D, its normalized value, or the output DAC (see Output). For example, the
output DAC resolution is 1 part in 54612 for 0-20mA output, or 1 part in 59577 for
±10V output.
Nominal input ranges may be
rescaled to smaller sub-ranges to
drive the output. The effective
input resolution is proportionally
diminished as you rescale input
spans below nominal losing 1-bit
every time you halve the range.
So be careful not to diminish
resolution below 12-bits
minimum (1 part in 4096) for
rated performance
Table 1: DT INPUT RESOLUTION PER INPUT PATH/RANGE PER MODEL
DTx36 INPUT RANGE
xDIVIDER
xGAIN
A/D INPUT RESOLUTION
1
A (TB1/TB3-1): ±20mA
24.9Ω Shunt
2
6658 - 58878 (1/52220)
A (TB1/TB3-1): 0-20mA
24.9Ω Shunt
2
32768 - 58878 (1/26110)
A (TB1/TB3-1): 4-20mA
24.9Ω Shunt
2
37990 - 58878 (1/20888)
A (TB1/TB3-1): 0-11.17mA
24.9Ω Shunt
2
32768 - 47350 (1/14582)
A (TB1/TB3-1): ±1mA
24.9Ω Shunt
32
11880 - 53656 (1/41776)
B (TB1/TB3-3): ±0.5VDC
NONE
2
6554 - 58982 (1/52428)
B (TB1/TB3-3): 0-0.5V DC
NONE
2
32768 - 58982 (1/26214)
DTx37 INPUT RANGE
xDIVIDER
xGAIN
A/D INPUT RESOLUTION
1
A (TB1/TB3-1): ±1V DC
NONE
1
6554 - 58982 (1/52428)
A (TB1/TB3-1): 0-1V DC
NONE
1
32768 - 58982 (1/26214)
B (TB1/TB3-3): ±10V DC
86.6K/1084.6K
1
11837 - 53699 (1/41862)
B (TB1/TB3-3): ±5V DC
86.6K/1084.6K
1
22303 - 43233 (1/20931)
B (TB1/TB3-3): 0-10V DC
86.6K/1084.6K
1
32768 - 53699 (1/20931)
B (TB1/TB3-3): 0-5V DC
86.6K/1084.6K
1
32768 - 43233 (1/10465)
DTx38 INPUT RANGE
xDIVIDER
xGAIN
A/D INPUT RESOLUTION
1
A (TB1/TB3-1): ±15V DC
28K/527K
1
11876 - 53660 (1/41784)
A (TB1/TB3-1): 0-15V DC
28K/527K
1
32768 - 53660 (1/20892)
B (TB1/TB3-3): ±150V DC
5.36K/1003.36
1
11762 - 53774 (1/42012)
B (TB1/TB3-3): ±75V DC
5.36K/1003.36
1
22265 - 43271 (1/21006)
B (TB1/TB3-3): 0-150V DC
5.36K/1003.36
1
32768 - 53774 (1/21006)
B (TB1/TB3-3): 0-75V DC
5.36K/1003.36
1
32768 - 43271 (1/10503)
1
Note:
AD_count = (Vin*Gain/1.25) * 32768+32768.
Optional AC Current Sensor (Model 5020-350, for AC Current IN to DT336 at TB1):
Optional sensor can be connected to TB1 of the DT336 model for AC current sensing
and is a toroidal instrument transformer that converts the sinusoidal 50-60Hz AC
current signal into low level 0 to 11.17mA DC. The input AC current range is a
function of the number of turns placed through the toroid as shown in Table 2 below.
This sensor is isolated and requires no calibration or adjustment. When used with a
DT336 module, it also facilitates AC current input isolation from the ADC voltage
input, as well as redundant input isolation with respect to each output of this
transmitter.
