DT238: High DC Voltage Input Two-Wire Dual Transmitter

DT230 series signal conditioners provide two independent I/O channels in a single, space-saving unit. The DT238 model is a two-wire dual transmitter that isolates and converts high-level DC voltage inputs to proportional 4-20mA control signals. Power is received from the output loop current or a DC supply when using a three-wire connection.

High-voltage isolation separates all input and output circuits from each other. Isolation protects from surges, reduces noise, and eliminates ground loop errors.

Setup and calibration are fast and easy with a convenient USB connection to your PC and Acromag’s Windows configuration software. The Android app enables setup with mobile devices.

Advanced signal processing capabilities, variable range input/output, and convenient USB programming make this instrument very versatile. These transmitters can withstand harsh industrial environments and operate reliably across a wide temperature range with very low drift. They feature RFI, EMI, ESD, EFT, and surge protection plus low radiated emissions.

Performance Specifications

IMPORTANT: To prevent ground loop error between a grounded PC and a grounded input signal, Acromag strongly recommends use of a USB isolator like Acromag’s USB-Isolator when configuring a DT230 Series transmitter.

USB Interface

USB Connection
Type: USB Mini-B type socket, 5-pin
Data Rate: 12Mbps. USB v1.1 and 2.0 compatible
Maximum cable length: 5.0 meters
Transient voltage suppression on power and data lines.

Input (two channels)

Default Configuration/Calibration
Input: ±150V, medium filter
Output: 4 to 20mA
Scaling Adjust: Full range
Input Impedance:
Path A: 15MΩ
Path B: 1MΩ
Input Over-Voltage Protection: Bipolar Transient Voltage Suppression (TVS) and diode clamping
Input Filter: RC filter plus variable digital filter (none, low, medium, high)
Input Bandwidth: -3dB @ 16Hz (no filtering)
Noise Rejection (@ 60Hz, no filter):
Common Mode: 70dB no filter (113dB high filter)
Normal Mode: Path A 32dB, Path B 51dB no filter (>80dB high filter)

Output (two channels)

D/A Converters (DAC): Two 16-bit D/A converters
Output Ranges: 4-20mA DC 3.5-24mA under/over-range capability
Output Accuracy: ±0.05%, typical. ±0.1%, maximum
Output Compliance:
Rload = (Vsupply – 7V) / 0.020A
Rload = 0 to 850 ohms @ 24V DC

Output Response Time (for step input change)

Time to reach 98% of output value (typical)
No filtering               34 milliseconds
Low filter                  62 milliseconds
Medium filter         195 milliseconds
High filter             1109 milliseconds

Output Ripple: Less than ±0.1% of output span

Environmental

Operating temperature
Operation: -40 to 80°C (-40° to 176°F)
Storage: -40 to 85°C (-40 to 185°F)
Relative humidity: 5 to 95% non-condensing
Power Requirement: Loop-powered, 7-32V DC SELV, 24mA max
Isolation: 1500V AC peak. 250V AC (354V DC) continuous isolation between input and output circuits
Shock and Vibration Immunity:
Vibration: 4g, per IEC 60068-2-6
Shock: 25g, per IEC 60068-2-27

Approvals (pending)
CE compliant. Designed for UL/cUL Class I Division 2 Groups ABCD, ATEX / IECEx Zone 2, II 3 G Ex nA IIC T4 Gc -40°C < Ta < +80°C

Electromagnetic Compatibility (EMC) Compliance
Radiated Emissions: BS EN 61000-6-4, CISPR 16
RFI: BS EN 61000-6-2, IEC 61000-4-3
Conducted RFI: BS EN 61000-6-2, IEC 61000-4-6
ESD: BS EN 61000-6-2, IEC 61000-4-2
EFT: BS EN 61000-6-2, IEC 61000-4-4
Surge Immunity: BS EN 61000-6-2, IEC 61000-4-5

Physical

General: General-purpose enclosure designed for mounting on 35mm “T-type” DIN rail
Case Material: Self-extinguishing polyamide, UL94 V-0 rated
I/O Connectors: Removable plug-in terminal blocks rated for 12A/250V; AWG #26-12, stranded or solid copper wire
Dimensions: 17.5 x 114.5 x 99.0 mm (0.7 x 4.51 x 3.90 inches)
Unit weight: 0.16 kg (0.35 pounds)
Shipping Weight: 0.22 kg (0.5 pounds) packed