EQXTCxx
Updated on January 22, 2025
The EQXTC06 is a six-channel thermocouple expansion module for EQSP32 Micro-PLC IoT controller, designed for precise temperature measurements in industrial applications.
Supporting K-type thermocouples, each module sequentially processes and updates all of its six channels. With up to 15 cascaded modules, a single EQSP32 may be equipped with up to 90 thermocouple sensors without adding to the system’s processing time.
The processed temperature data is automatically requested by the EQSP32 controller and made available locally, as if it were a native EQSP32 peripheral.
It incorporates ESD protection, integrated cold-junction compensation, and a high-resolution 14-bit signed conversion, delivering a nominal temperature resolution of 0.25°C.
With its integrated fault detection capabilities, the reliable operation is ensured by quickly highlighting and addressing potential wiring issues. The fault detection includes identifying thermocouple shorts to GND or VCC as well as open sensor connections.
Housed in a space-efficient DIN-rail mountable enclosure, tailored for easy installation and organized wiring within control cabinets. Its design includes high-quality screw terminals, ensuring secure and reliable connections for thermocouple sensors, minimizing the risk of disconnections in industrial settings.
Designed for industrial environments, the module operates reliably in temperatures ranging from -20°C to +55°C and features IP20 protection.
The EQXTC06 is automatically detected by the EQSP32 upon power-up, functioning seamlessly as a native peripheral. Powered directly through the EQSP32’s board-to-board connector, it eliminates the need for additional power supplies. This plug-and-play capability simplifies setup, enabling users to expand their systems with minimal effort or configuration.
Firmware updates are easily applied through its front-facing USB-C port, ensuring quick access to the latest features and improvements. This update mechanism minimizes downtime and maintains optimal functionality without removing the module from the system. The front-facing LEDs provide visual indicators for power and operational status, for easy assessment of module’s state.
The EQXTC06 is supported by the EQ-AI generative AI model, simplifying programming and integration by assisting in code generation. This innovative approach reduces complexity and accelerates deployment, making advanced industrial solutions accessible to users with varying technical expertise.
Key Features
- Six-channel support for K-type thermocouples.
- High-resolution 14-bit signed conversion with 0.25°C nominal temperature resolution.
- Integrated cold-junction compensation for precise ambient temperature adjustment.
- Fault detection for shorts to GND, VCC, and open thermocouple connections.
- ESD protection up to ±2kV (Human Body Model).
- Compact DIN-rail mountable design for organized installation.
- Automatic detection by EQSP32.
- LED indicators for power and status monitoring.
- Front-facing USB-C port for convenient firmware updates.
- Powered directly by EQSP32, no external power supply required.
- Simplified integration with EQ-AI generative AI for easy code generation.
- Compact, 2SU-wide (36mm), DIN-rail mount enclosure with 12 screw terminals.
- Temperature range -20°C to +55°C.
Applications
- Industrial temperature monitoring.
- Process control systems.
- HVAC system management.
- Furnace and kiln control.
- Food and beverage processing.
- Plastic and rubber manufacturing.
- Pharmaceutical production.
- Energy and utility monitoring.
- Oil and gas operations.
- Environmental monitoring.
- Laboratory and research equipment.
- Automotive manufacturing.
- Semiconductor industry applications.
- Textile industry processes.
- Cold chain logistics.
- Building automation systems.
- Aerospace testing.
- Brewing and distillation.
- Waste management systems.
- Pulp and paper industry processes.
Block Diagram
System Specifications
Section | Features |
Power Management | Supplied by the board-to-board connector |
Thermocouple Inputs | 6 x K-type thermocouple sensor inputs |
14-bit signed temperature readings with 0.25°C nominal temperature resolution | |
Integrated cold-junction compensation | |
ESD protection up to ±2kV (Human Body Model) | |
Shorted sensor to GND or VCC, and open sensor | |
Indications | Green LED for power indication |
Red LED for device status | |
Enclosure | Easy standard DIN rail push-fit mounting with spring mechanism |
IP20 | |
Expandability | Push fit expansion module mounting |
Automatic module detection and characterization | |
Firmware Update | Front-facing USB-C for easy firmware upgrades |
Environment | -20°C to 55°C |
Electrical Specifications
Absolute maximum values
Pin | Type | Min. | Typ. | Max. | Unit |
T+, T- to GND | Analog Input | -0.3 |
| 3.6 | V |
T+, T- ESD (Human body model) | Analog Input | -2000 |
| 2000 | V |
Connecting EQXTC
To use the EQXTC thermocouple sensor expansion module, mount it next to the EQSP32 controller on the DIN rail and simply slide it until the board-to-board connector is fully inserted into EQSP32.
The expansion module is powered by the board-to-board connector and does not require an external power supply.
When adding additional modules, it is recommended that the power is disconnected from the system. After adding the expansion modules and powering up the system, EQSP32 will start the automatic detection and indexing process.
For safety and ease of use, it is strongly recommended that a main circuit breaker is used to completely isolate the AC/DC from the grid.
Warning: Make sure that the appropriate ground fault circuit breaker, fuses or circuit breakers and any other necessary protective components are used if there is any risk of user electrocution.
Visual and Audio Indications
When the module is connected and the system is powered on, the POWER LED should light up solid green.
If the STATUS LED is solid red after the automatic detection, it means that the EQXTC module has encountered a communication issue.
During data exchange between the main EQSP32 unit and the EQXTC module, the STATUS LED will be flashing for each transaction.
Power LED
On – Powered On
Off – No Power
Status LED
Off – No errors, no communication
Flashing – Data exchange
On – Communication error
Pinout
Industrial IoT Controller
X1 - Screw terminal connector 1
USB-C - Firmware update port
X2 - Screw terminal connector 2
Industrial IoT Controller
X1 - Screw terminal connector 1
The X1 connector provides wiring connections for thermocouple sensors’ channels 1, 2, and 3, marked as TC1, TC2 and TC3 respectively.
Name | Pin | Function | Type |
X1 | T1+, T2+, T3+ | Positive thermocouple terminal (+) | ANALOG IN |
T1-, T2-, T3- | Negative thermocouple terminal (-) | ANALOG IN |
X2 - Screw terminal connector 2
The X2 connector provides wiring connections for thermocouple sensors’ channels 4, 5, and 6, marked as TC4, TC5 and TC6 respectively.
Name | Pin | Function | Type |
X2 | T4+, T5+, T6+ | Positive thermocouple terminal (+) | ANALOG IN |
T4-, T5-, T6- | Negative thermocouple terminal (-) | ANALOG IN |
Power Distribution
EQXTC’s core and peripherals are powered by EQSP32’s power management unit via the board-to-board connector.
The board-to-board connector carries the power lines for system operation and the communication bus for allowing the expansion modules to interact with the main EQSP32 unit.
EQXTC’s control unit may also be powered by the front facing USB-C port. By connecting the thermocouple sensor expansion module via the USB-C port, the system’s core will be powered on. This allows for easy firmware update without being connected to the EQSP32 or any external power supply.
Thermocouple Sensor Inputs
Equivalent Thermocouple Conditioning and Measurement Circuit
Thermocouple Wiring
The thermocouple sensor provides precise temperature measurement by utilizing the voltage generated at the thermocouple junction.
Each thermocouple channel includes two terminals (T+ and T-) for connecting the thermocouple wires. The EQXTC amplifies and measures the voltage generated at the junction to determine the temperature.
Additionally, the module measures the ambient temperature to apply cold-junction compensation, ensuring accurate readings regardless of external temperature variations.
Library Reference | |
Usage | |
eqsp32.readPin( EQXTC(ii, nn) ) | Returns the temperature in degrees Celsius ii: number (index) of EQXTC module on the chain (*) nn: EQXTC channel number (1 to 6 for thermocouple channels, 7 for module’s internal temperature) |
Note:
(*) For 2 EQXTC modules connected on the main unit, the first one (closer to the main unit) will have an index of 1, the second EQXTC index of 2 etc.
The index refers only to the same type of modules. Different types of modules will be indexed with their own type.
Boot Button & Firmware Update
Boot Button
The Boot button is only used for entering EQXTC module into firmware update mode (or maintenance mode). To enter maintenance mode, keep the boot button pressed while powering up the module.
Another option is to keep the boot button pressed while sending a reset command to the module via the serial terminal.
Once the module is in maintenance mode, it will be shown as a storage device. Drag and drop the desired .uf2 firmware file into the RPI-RP2 storage device and the update will be performed automatically.
Once the update is done, the unit will be automatically rebooted.
Power cycle the system to trigger the automatic detection procedure and the system will be ready for normal operation.
Mechanical Dimensions
All dimensions are measured in mm with a +/-0.1 tolerance.
