TT237: Voltage Input, Loop-Power, 2-Wire Transmitter

The TT237 model is a space-saving two-wire transmitter that isolates and converts a process level DC voltage input to a proportional 4-20mA control signal. A single unit supports multiple voltage input ranges for extra flexibility. Power is received from the output loop current or a local DC supply when using a three-wire connection.

High-voltage isolation separates the input from the output circuit. 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.

Advanced signal processing capabilities, variable range input, and convenient USB programming make this instrument a very versatile temperature measurement device. 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 damage or errors from grounded PCs and surges, Acromag strongly recommends the use of their USB-ISOLATOR when configuring a TT230 Series transmitter.

USB Interface

USB Connector: USB Mini-B type socket, 5-pin
USB Data Rate: 12Mbps. USB v1.1 and 2.0 compatible
USB Transient Protection: Transient voltage suppression on power and data lines
USB Cable Length: 5.0 meters maximum
Driver: Not required. Uses built-in Human Interface Device (HID) USB drivers of the Windows operating system

Input

Default Configuration/Calibration:
Input: ±10V DC, medium filtering
Output: 4 to 20mA

Input Ranges and Accuracy:
Range                   Accuracy
±1V DC            ±0.05% of span
±5V DC            ±0.05% of span
±10V DC         ±0.05% of span
Error includes the effects of repeatability, terminal point conformity, and linearization.

Ambient Temperature Effect: Better than ±80ppm/°C (±0.008%/°C)
Zero Scaling Adjust: 0 to 95% of range, typical
Full Scale Adjust: 5 to 100% of full scale range, typical
Input Impedance:
±1V input: 15M ohms
±5V input: >1M ohms
±10V input: >1M ohms

Input Over-Voltage Protection: Bipolar Transient Voltage Suppressers (TVS), 14V working and 18V clamp level typical
Input Resolution:
Bipolar input: 1 part in 50000 (±25000)
Unipolar input: 1 part in 25000
Input Filter: Selectable digital filtering settings (low, medium, high)
Input Filter Bandwidth:
Normal mode plus digital filtering within the ADC Bandwidth (-3dB) varies with digital filter setting from 4Hz without filtering to 0.33Hz with high filtering.
Noise Rejection (Common Mode, High Filter): 130dB @ 60Hz, typical with 100 ohm input unbalance

Output

Output Range: 4 to 20mA DC
Output Compliance:
Rload = (Vsupply – 11V) / 0.020A
Rload = 0 to 650 ohms @ 24V DC

Output Response Time (for step input change)

Time to reach 98% of output value (typical)
Low filter                  50 milliseconds
Medium filter        150 milliseconds
High filter             1200 milliseconds

Environmental

Operating temperature: -40 to 80°C (-40° to 176°F)
Storage temperature: -40 to 85°C (-40 to 185°F)
Relative humidity: 5 to 95% non-condensing
Power requirement: 12-32V DC SELV (Safety Extra Low Voltage), 24mA maximum
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
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
Approvals:
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

Physical

General: General-purpose enclosure designed for mounting on 35mm “T-type” DIN rail
Case Material: Self-extinguishing polyamide, UL94 V-0 rated, color light gray. General-purpose NEMA Type 1 enclosure
I/O Connectors: Removable plug-in terminal blocks rated for 12A/250V; AWG #26-12, stranded or solid copper wire
Dimensions: 12.5 x 114.5 x 99.0 mm (0.5 x 4.51 x 3.90 inches)
Shipping Weight: 0.22 kg (0.5 pounds) packed