Product Description

Allen-Bradley 1756-IT16 — ControlLogix 16-Channel Thermocouple / mV Input Module

Temperature measurement in industrial control systems demands more than just counting pulses — it needs precision, stability, and broad sensor compatibility across varied process conditions. The 1756-IT16 delivers all of that within a single ControlLogix chassis slot, handling 16 thermocouple or millivolt input channels with 24-bit resolution and ITS-90 linearization that covers nine standard thermocouple types without requiring separate signal conditioning hardware.

Technical Specifications

Parameter	Value
Catalog Number	1756-IT16
Series	A
Platform	Allen-Bradley ControlLogix
Input Channels	16 (Thermocouple / mV mode)
Input Type	Non-Isolated, High-Density
Input Range	–100 to +100 mV
Peak Input Voltage	±30 VDC (overvoltage protection)
Resolution	24-bit
Measurement Precision	0.01 µV/count (–101 to +101 mV)
Thermocouple Types	B, C, E, J, K, N, R, S, T
TC Linearization	ITS-90
CJC Sensors Required	2 × 1756-CJC (ordered separately)
Normal Mode Noise Rejection	75 dB at 60 Hz
Current Draw @ 5.1 VDC	200 mA
Current Draw @ 24 VDC	80 mA
Max Power Dissipation	3 W
Thermal Dissipation	9.9 BTU/hr (max)
Continuous Isolation Voltage	250 V
Operating Temperature	0–60°C (32–140°F)
Mounting	ControlLogix chassis (local or remote)
Enclosure	Open style (chassis-mounted)
Status Indicator	LED
Terminal Connection	Plug-in (RTB)
Certifications	CE, c-UL-us, RCM, Ex, KC, EAC, IECEx

16 Channels, One Slot — Why Density Matters

Rack space in a ControlLogix system isn't free. Every slot occupied by a specialty module is one fewer slot available for other I/O, communication, or motion functions. The 1756-IT16's 16-channel density means that a system monitoring a large number of thermocouple points — furnaces, reactors, heat exchangers, or multi-zone ovens — can consolidate that sensing into a single module rather than spreading it across multiple cards.

For applications with 8 or fewer channels, the isolated 1756-IT6I provides channel-to-channel isolation. But where high channel count and chassis economy take priority, the 1756-IT16 is the right tool.

Nine Thermocouple Types Under One Roof

One of the practical strengths of this module is sensor breadth. A single 1756-IT16 can simultaneously handle:

Type	Typical Temp Range	Common Applications
J	–210 to +1200°C	General industrial, mild environments
K	–270 to +1372°C	Most widely used general purpose
T	–270 to +400°C	Food processing, cryogenic
E	–270 to +1000°C	High sensitivity at moderate temps
N	–270 to +1300°C	High-temp stability, oxidizing environments
B	+200 to +1820°C	Very high temperature processes
R	–50 to +1768°C	Platinum, lab and industrial furnaces
S	–50 to +1768°C	Platinum, high-purity metal processing
C	0 to +2315°C	Extreme temperature, vacuum/inert atmospheres

Mixed-type installations — common in plants that have evolved over time with different sensor specifications across zones — can all land on a single 1756-IT16, simplifying wiring, sparing, and module configuration.

mV Mode: Beyond Thermocouple Inputs

When thermocouple mode isn't needed, the module operates as a direct millivolt input across the –100 to +100 mV range with 0.01 µV/count resolution. This makes it usable for any low-level analog signal source that produces a small voltage — including custom sensor outputs, bridge circuits, or legacy transmitters that output mV-scale signals rather than 4–20 mA loops.

Cold Junction Compensation — What to Order

The 1756-IT16 requires two 1756-CJC cold junction compensation sensors for proper thermocouple operation. These are not included with the module and must be ordered separately. The CJC sensors mount in the module's terminal block and allow the module to compensate for temperature variations at the point where thermocouple wire meets the terminal, which is essential for maintaining measurement accuracy at the reference junction.

Certifications & Compliance

The 1756-IT16 carries approvals from CE, c-UL-us, RCM, Ex (hazardous locations), KC (South Korea), EAC (Eurasian), and IECEx — a certification package that supports deployment in international facilities and across a wide range of regulated industries including chemical processing, oil & gas, and food production.

Where This Module Gets Used

The 1756-IT16 fits naturally into temperature-intensive control applications:

Multi-zone furnace and kiln temperature control
Heat exchanger monitoring in chemical plants
Pasteurization and sterilization systems in food & beverage
Reactor temperature profiling in pharmaceutical manufacturing
Boiler and steam system management
Die casting and injection molding thermal monitoring

Frequently Asked Questions

Q: Do the 1756-CJC sensors come included with the 1756-IT16?

A: No. The two required CJC (cold junction compensation) sensors, catalog number 1756-CJC, are sold separately and must be ordered alongside the module if you intend to use it in thermocouple mode. Without the CJC sensors installed in the terminal block, thermocouple measurements will lack proper reference junction compensation.

Q: What thermocouple types does the 1756-IT16 support?

A: The module supports nine IEC/ANSI standard thermocouple types: B, C, E, J, K, N, R, S, and T. Each channel can be independently configured for a different type, so mixed-sensor installations are fully supported within a single module.

Q: Can the 1756-IT16 be used for millivolt signals that are not from thermocouples?

A: Yes. When configured in mV mode rather than thermocouple mode, the module accepts any signal in the –100 to +100 mV range at 0.01 µV/count precision. This makes it usable for strain gauge bridges, custom transducers, and other low-level analog sources.

Q: What is the difference between the 1756-IT16 and the 1756-IT6I?

A: The primary difference is channel isolation and count. The 1756-IT16 provides 16 non-isolated channels at high density — all channels share a common reference. The 1756-IT6I provides 6 individually isolated channels, meaning each channel is fully isolated from the others and from the backplane. The isolated version is preferred when ground loops or electrical noise between measurement points is a concern; the 1756-IT16 is the choice when high channel count and slot efficiency matter more than channel-to-channel isolation.

Q: How is the 1756-IT16 mounted and connected to field wiring?

A: The module mounts directly into any ControlLogix 1756 chassis slot, local or remote. Field wiring connects through a plug-in removable terminal block (RTB), which allows the module to be removed from the chassis without disturbing the field wiring — a meaningful advantage during maintenance or module replacement.

Q: What certifications does the 1756-IT16 carry?

A: Approvals include CE, c-UL-us, RCM, Ex (for hazardous location use), KC, EAC, and IECEx — covering major international markets and regulated industrial environments.

Q: What does "Genuine Series A" mean for this listing?

A: The unit is an authentic Allen-Bradley manufactured module, Series A revision, new and unused in original packaging. It has not been refurbished, repaired, or previously installed.

Q: What is the operating temperature range for the 1756-IT16?

A: The module is rated for operation from 0°C to 60°C (32°F to 140°F), consistent with standard ControlLogix platform environmental specifications for panel and enclosure mounting.

1756-IT16 Genuine 1756IT16 AB Ser A ControlLogix 16-Channel TC/MV Input Module