NFAI143-H50/A4S00

The Yokogawa NFAI143-H50/A4S00 is a 16-channel isolated analog input module for acquiring 4-20 mA current signals from field transmitters. It supports HART communication, configurable 2-wire or 4-wire transmitter connections on each channel, and a 10 ms data refresh cycle. The specified configuration includes a pressure clamp terminal block, model NFTA4S-00, for field wiring.

Input Configuration and Signal Processing

The module accepts 4-20 mA analog signals across 16 isolated input channels. Its specified accuracy is +/-0.1% of full scale, with a maximum temperature drift of +/-0.01% per deg C. The 10 ms data refresh cycle defines how frequently input data is updated, while the 100 ms input step response time describes the specified response to a change in the input signal.

Each channel can be configured for a 2-wire or 4-wire transmitter using a setting pin. The module provides a transmitter supply of 24.0 to 25.5 V, with an output current limit of 25 mA. The allowable input current is 24 mA, and overcurrent protection is provided.

Electrical Characteristics

The input-to-system withstand voltage is 1500 V AC for 1 minute. Input resistance is 250 ohms when the module is powered on and 500 kohms or more when powered off. These values are relevant when checking current-loop loading and evaluating the module's electrical isolation requirements.

The listed maximum current consumption is 230 mA at 5 V DC and 540 mA at 24 V DC. The transmitter supply output is separate from these module consumption ratings and has its own 25 mA current limit.

Model Configuration

The ordering code identifies the communication option, protection configuration, basic type, and terminal block option. Yokogawa's published specifications identify -H as the HART communication option, 5 as the configuration without explosion protection, 0 as the basic type, and /A4S00 as the analog pressure clamp terminal block option, NFTA4S-00.

Parameter	Specification
Model	NFAI143-H50/A4S00
Brand	Yokogawa
Product Type	Isolated Analog Input Module
Input Channels	16, isolated
Input Signal	4-20 mA
HART Communication	Supported
Allowable Input Current	24 mA
Input Resistance, Power On	250 ohms
Input Resistance, Power Off	500 kohms or more
Input-to-System Withstand Voltage	1500 V AC for 1 minute
Overcurrent Protection	Provided
Accuracy	+/-0.1% of full scale
Data Refresh Cycle	10 ms
Input Step Response Time	100 ms
Transmitter Supply	24.0-25.5 V
Transmitter Supply Output Current Limit	25 mA
Transmitter Configuration	2-wire or 4-wire, selected per channel by setting pin
Temperature Drift	Maximum +/-0.01% per deg C
Maximum Current Consumption	230 mA at 5 V DC; 540 mA at 24 V DC
Terminal Block	NFTA4S-00, pressure clamp type
Explosion Protection Configuration	No explosion protection
Basic Type	0
Weight	0.3 kg

Frequently Asked Questions

Q: Does the NFAI143-H50/A4S00 support HART communication?

A: Yes. The -H suffix identifies the HART communication option. HART communication uses the same 4-20 mA current loop for analog measurement and superimposed digital communication; verify the host system's HART configuration when planning instrument access.

Q: Can the module accept signals from both 2-wire and 4-wire transmitters?

A: Yes. The module specification provides a per-channel setting pin for selecting 2-wire or 4-wire transmitter configuration. Check the transmitter wiring and supply requirements before connecting each loop.

Q: Is the NFAI143-H50/A4S00 suitable for an explosion-protected installation?

A: The 5 configuration code specifies no explosion protection. Do not treat this version as an explosion-protected module; select equipment and interface components according to the installation's applicable hazardous-area requirements.

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