FUJI NP1AXH4-TC I/O Module | 4 Ch Thermocouple Input

This standard I/O module provides thermocouple input capability for FUJI MICREX-SX automation systems. It directly connects temperature sensors without external signal conditioning. Therefore, it enables precise temperature measurement for industrial heating and process control.

Physical and Analog Specifications

The FUJI NP1AXH4-TC measures 13.0 cm in length and 9.5 cm in width. Moreover, its module weight equals approximately 0.30 kg for DIN rail mounting. A single 20-pin removable terminal block handles all field wiring connections. Additionally, this module contains four independent thermocouple input channels.

Parameter	Specification
Brand	FUJI Electric
Full Model	NP1AXH4-TC
Category	Standard I/O Module (Thermocouple Input)
Dimensions (L x W x H)	13.0 cm x 9.5 cm x 6.0 cm (5.12″ x 3.74″ x 2.36″)
Module Weight	0.30 kg (0.66 lbs)
Primary Interface	1 x 20-pin Removable Screw Terminal Block
Backplane Interface	1 x 48-pin Male Connector (MICREX-SX Rack)
Operating Voltage	24 VDC from Backplane (19.2 to 28.8 VDC)
Power Consumption	2.5 W (Typical)
Analog Input Channels	4 Differential Channels
Input Type	Thermocouple (Direct Connection)
Supported Thermocouples	Type K, J, E, T, R, S, B
Input Voltage Range	-10 mV to +70 mV (Thermocouple Range)
Cold Junction Compensation	Internal (Automatic)
Resolution	16 Bits (0 to 65535 Counts)
Conversion Type	Sigma-Delta
Conversion Speed	100 ms per Channel (400 ms for All 4 Channels)
Absolute Accuracy	±0.3% of Full Scale at 25°C
Accuracy Drift	±0.01% per °C
Common Mode Rejection	120 dB (50/60 Hz)
Normal Mode Rejection	80 dB (50/60 Hz)
Input Impedance	2 MΩ (Typical)
Maximum Input Voltage	±30 VDC (Continuous)
On-Board Components	1 ADC Chip + 4 Signal Conditioning Circuits + 1 Temperature Sensor (CJC) + 4 Protection Diodes + 1 EMI Filter + 1 Voltage Reference IC
Energy Storage	3 x 100 µF Electrolytic Capacitors (35V) + 2 x 10 µF Tantalum (25V)
Isolation Rating	1500 Vrms (Field to Logic)
Operating Temperature	0°C to +55°C (32°F to 131°F)
Mounting Type	DIN Rail or MICREX-SX PLC Rack
Status Indicators	1 Green LED (Power) + 1 Green LED (Active) + 1 Red LED (Fault) + 4 Green LEDs (Channel Valid)

Thermocouple Input and Cold Junction Compensation

The FUJI NP1AXH4-TC accepts direct connection from seven common thermocouple types. Specifically, Type K, J, E, T, R, S, and B are all supported. In addition, an internal temperature sensor provides automatic cold junction compensation. Moreover, the module linearizes the thermocouple signal for accurate temperature readings. Consequently, you do not need external transmitters or signal conditioners.

High-Resolution and Noise Rejection Features

This standard I/O module uses a sigma-delta converter with 16-bit resolution. For instance, the 120 dB common mode rejection eliminates ground loop noise effectively. In addition, the 80 dB normal mode rejection filters 50/60 Hz power line interference. Furthermore, the conversion speed of 100 ms per channel suits most process applications. Thus, this module delivers stable and accurate temperature readings in noisy industrial environments.

Energy Storage and Signal Integrity

This I/O module stores energy using five onboard capacitors for power filtering. Specifically, three electrolytic capacitors smooth the 24 VDC supply for stable ADC operation. In addition, two tantalum capacitors provide high-frequency noise suppression for analog circuits. Furthermore, these capacitors maintain conversion accuracy during brief power interruptions. Therefore, the FUJI NP1AXH4-TC rejects electrical noise from factory environments effectively.

Installation and Diagnostic Indicators

Seven LED indicators provide operational status at a glance on this module. First, a green Power LED lights when the 24 VDC backplane supply is present. Second, a green Active LED flashes during normal analog conversion operation. Third, a red Fault LED indicates hardware errors or out-of-range temperatures. Additionally, four green Channel Valid LEDs illuminate when each channel reads a valid thermocouple signal. Thus, you can diagnose sensor status instantly without external tools.