TT235: Isolated RTD Input, Loop Power, 2-Wire Transmitter

The TT235 model is a space-saving two-wire transmitter that isolates and converts an RTD sensor input to a proportional 4-20mA signal. Power is received from the output loop current or a DC supply when using a three-wire connection. The transmitter provides sensor excitation plus performs linearization, lead-wire compensation, and lead-break detection.

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
100Ω Pt RTD, α=0.00385, -200 to 850°C input,
4-20mA output, upscale break detect, medium filter.

Input Configuration:
Two- three- or four-wire sensor input connections.
Programs in °C, °F, °K, or ohmic integer values only

Input Ranges
Input Type                                  Range                     Accuracy**
RTD, Pt 100Ω                          -200 to 850°C               ±0.25°C
RTD, Pt 200Ω                         -200 to 850°C                ±0.30°C
RTD, Pt 500Ω                         -200 to 850°C                ±0.50°C
RTD, Pt 1000Ω                       -200 to 850°C                ±1.00°C
Ni 120Ω (Minco 7-120)          -80 to 320°C                ±0.08°C
Cu 10Ω (Minco 16-9)           -200 to 270°C                 ±1.00°C
Resistance (linear)                     0 to 25Ω                    ±0.05Ω
Resistance (linear)                     0 to 450Ω                  ±0.10Ω
Resistance (linear)                     0 to 9000Ω               ±0.90Ω
Resistance (linear)                     0 to 2250Ω               ±2.25Ω
Resistance (linear) *                   0 to 4500Ω              ±4.50Ω

*Note 1: Linear resistance input range approaches but does not include 0Ω and 500Ω. If exactly 0Ω or 500Ω is measured, break detection is triggered.
**Note 2: Rated accuracy (in °C and % of span) applies for input spans greater than 5% of input full-scale.

Input Scaling Adjust:
Zero: 0 to 95% of range, typical.
Full scale: 5 to 100% of full scale range, typical.

Lead Break (Sensor Burnout) Detection: Configurable for either upscale or downscale.

Output

Output Range: 4 to 20mA DC.
Under-range capability 3.5mA.
Over-range capability 24mA.

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

Output DAC Resolution: 16-bit D/A converter.

Output Accuracy: Better than ±0.05% of span, typical (±0.1% max) for nominal input spans. Includes the effects of repeatability, terminal point conformity, and linearization, but does not include sensor error.

Ambient Temperature Effect: Better than ±0.008% per °C of input span or ±80ppm/°C, typical. Includes the combined effects of zero and span drift over temperature.

Output Response Time (for step input change)
No filter                 22ms
Low filter              50ms
Medium filter    160ms
High filter         1210ms

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.

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.

Additional information