The Allen-Bradley 1734-IT2I is a 2-channel thermocouple and millivolt input module engineered for seamless integration within the Rockwell Automation POINT I/O distributed control architecture. Rather than functioning as a standalone measurement device, the 1734-IT2I is designed to operate as a precision temperature acquisition node within a layered automation system — coordinating with the control layer, I/O network layer, power distribution layer, and field execution layer to deliver consistent, high-resolution thermal data across the entire process loop.
In a typical POINT I/O deployment, the 1734-IT2I mounts directly onto a 1734-TB or 1734-TBS terminal base, which provides both the mechanical interface and the field wiring connection point. The module communicates upstream through the POINT I/O adapter — such as the 1734-AENT EtherNet/IP adapter or the 1734-ADNX DeviceNet adapter — which bridges the distributed I/O nodes to the primary control backplane. This architecture allows the 1734-IT2I to deliver real-time thermocouple data to a CompactLogix L3x or L4x series controller, or to a ControlLogix 1756-L7x processor via a 1756-EN2T EtherNet/IP communication module, without requiring dedicated analog input cards at the main rack.
The modular nature of the POINT I/O platform means that the 1734-IT2I can be deployed at remote field junction boxes, process skids, or distributed panel locations — reducing field wiring runs and improving signal integrity. When paired with a 1734-EP24DC or 1734-EPAC power distribution module, the I/O segment maintains stable 24 VDC bus voltage even under varying field load conditions, ensuring that thermocouple signal conditioning circuits operate within their specified accuracy range across the full ambient temperature envelope.
Product Specification Table
| Parameter |
Specification |
| System Role |
Distributed Thermocouple / mV Input Node — POINT I/O Architecture |
| Input Channels |
2 (differential thermocouple or millivolt input) |
| Thermocouple Types Supported |
J, K, T, E, R, S, B, N (IEC 60584 compliant) |
| mV Input Range |
±150 mV |
| Resolution |
16-bit (including sign) |
| Accuracy |
±1°C typical (type K, at 25°C ambient) |
| Supply Voltage |
5 VDC (via POINT I/O bus); 24 VDC field power via terminal base |
| Current Consumption |
30 mA @ 5 VDC (backplane); 0 mA @ 24 VDC (no field power required) |
| Communication Interface |
POINT I/O backplane bus (EtherNet/IP, DeviceNet, ControlNet via adapter) |
| Open-Wire Detection |
Yes — per channel |
| Isolation |
500 VAC channel-to-backplane |
| Operating Temperature |
0°C to +55°C (IEC 60068-2-1/2) |
| Relative Humidity |
5% to 95% non-condensing |
| Mounting |
1734-TB or 1734-TBS terminal base (DIN rail) |
| Certifications |
UL, CE, cUL, ATEX Zone 2 (with appropriate housing) |
| Warranty |
12-Month Warranty — tested, verified, and ready for system integration |
System Compatibility Notes
The 1734-IT2I achieves its full architectural value when deployed as part of a coordinated POINT I/O segment. A typical temperature monitoring segment for a process control application might include the 1734-IT2I alongside a 1734-IB8 8-point 24 VDC digital input module for process status signals, a 1734-OB8 digital output module for actuator control, and a 1734-IE4C 4-channel current input module for 4–20 mA transmitter signals. Together, these modules share a common terminal base rail and communicate through a single 1734-AENT EtherNet/IP adapter, minimizing cabinet footprint while maximizing I/O density.
At the control layer, the thermocouple data collected by the 1734-IT2I is processed by a CompactLogix 1769-L36ERM controller using Logix 5000 ladder or function block programming. For larger installations requiring redundant control, the data path extends through a 1756-EN2T EtherNet/IP bridge module to a ControlLogix 1756-L74 processor operating in a redundant chassis pair with a 1756-RM2 redundancy module. This architecture ensures that temperature loop data remains available to the control system even during a controller switchover event, which is critical in continuous process industries such as petrochemical refining or power generation.
At the human-machine interface layer, temperature trends from the 1734-IT2I are visualized on a PanelView Plus 7 terminal (2711P-T10C21D8S) via FactoryTalk View ME, providing operators with real-time thermal profiles and alarm annunciation. The EtherNet/IP network backbone — typically structured as a linear or ring topology using managed switches — carries both I/O data and HMI communications on the same physical infrastructure, simplifying network architecture and reducing hardware costs.
For power layer integrity, the POINT I/O segment housing the 1734-IT2I is typically fed from a 1606-XLP72E or 1606-XLS240E power supply, which provides regulated 24 VDC with active power factor correction and diagnostic output signaling. This ensures that the sensitive analog front-end of the 1734-IT2I operates within its specified supply voltage window, preserving measurement accuracy across the full production shift.
Industrial Application Notes
The 1734-IT2I is widely deployed across industries where precise temperature measurement is a critical process variable integrated into the broader control architecture:
Petrochemical and Refining: In distillation column control systems, the 1734-IT2I monitors tray temperatures at multiple elevations, feeding data to a CompactLogix or ControlLogix controller that adjusts reflux ratios and reboiler duty via analog output modules and variable frequency drives. The module’s open-wire detection capability ensures that a failed thermocouple is immediately flagged, preventing undetected process deviations.
Power Generation: In turbine inlet temperature monitoring applications, the 1734-IT2I is deployed in distributed POINT I/O panels located near the turbine skid, with data transmitted over EtherNet/IP to the main control room DCS integration gateway. The module’s 500 VAC channel-to-backplane isolation protects the control network from high-voltage transients common in generator environments.
Metallurgy and Heat Treatment: Furnace temperature profiling systems use multiple 1734-IT2I modules — each monitoring two thermocouple zones — to build a complete thermal map of the furnace chamber. The data is used by the Logix controller to implement multi-zone PID temperature control, coordinating with SCR power controllers and cooling water valve actuators to maintain tight temperature uniformity across the load.
Food and Beverage Processing: Pasteurization and sterilization systems require continuous temperature verification at critical control points. The 1734-IT2I, mounted in IP65-rated enclosures with appropriate terminal bases, provides the temperature data required for HACCP compliance logging, with records archived via FactoryTalk Historian to a plant-level MES system.
Water and Wastewater Treatment: In anaerobic digester temperature control applications, the 1734-IT2I monitors process fluid temperatures and feeds the data to a CompactLogix controller managing heat exchanger bypass valves and recirculation pump speeds, ensuring optimal biological process conditions year-round.
Product Compatibility FAQ
Q1: Is the 1734-IT2I compatible with both EtherNet/IP and DeviceNet POINT I/O adapter configurations?
Yes. The 1734-IT2I communicates via the POINT I/O backplane bus and is adapter-agnostic. It operates identically whether the segment adapter is a 1734-AENT (EtherNet/IP), 1734-ADN (DeviceNet), or 1734-ACNR (ControlNet). The choice of adapter determines the upstream network protocol, while the module’s local I/O function remains unchanged. This flexibility allows the same 1734-IT2I hardware to be redeployed across different network architectures without modification.
Q2: What terminal base is required, and can the 1734-IT2I be installed in an existing POINT I/O segment without disrupting other modules?
The 1734-IT2I requires a 1734-TB (screw terminal) or 1734-TBS (spring clamp terminal) base. In an existing POINT I/O segment, modules can be added by inserting a new terminal base into the rail and connecting it to the adjacent base’s side connector — no segment power interruption is required for mechanical installation. However, the adapter’s I/O configuration must be updated in the Logix project to recognize the new module before it will communicate. Our team provides full commissioning support under the 12-Month Warranty coverage period.
Q3: What does the 12-Month Warranty cover, and how does ZYPLC support long-term architectural maintenance?
The 12-Month Warranty covers verified functional performance of the 1734-IT2I across all specified operating parameters, including channel accuracy, open-wire detection, backplane communication, and isolation integrity. ZYPLC maintains inventory of POINT I/O modules and associated components — including terminal bases, adapters, and power distribution modules — to support rapid replacement in the event of field failures. For long-term architectural maintenance, we offer cross-reference support to identify compatible replacement modules and can advise on migration paths to current-generation POINT I/O or Compact 5000 I/O platforms as part of a planned system lifecycle strategy.
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