Yokogawa NFA841-S00/A4S00 CENTUM CS 3000 Analog Input Module
The Yokogawa NFA841-S00/A4S00, also cataloged as the NFA841 Analog Input Module, operates as a dedicated hardware component for 8-channel analog signal acquisition and digitization within Yokogawa CENTUM CS 3000 DCS platforms. It conditions incoming field process signals—including 4-20 mA DC, 1-5 V DC, thermocouple, and RTD inputs—for direct internal controller processing and backplane distribution.
Suffix Breakdown & Model Matrix
The NFA841 model structure incorporates specific suffix coding to designate functional hardware variations and terminal connection options:
- NFA841: Base Model Designation (8-channel analog input module architecture)
- -S: Standard Signal Type/Execution Specification
- 00: Standard Hardware/Functionality Option Code
- /A4S00: Terminal Block Assembly Variant Code (Integrated pressure clamp/screw terminal connection configuration)
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | NFA841-S00/A4S00 |
| Brand | Yokogawa |
| Origin | Japan |
| Weight | Standard DCS Module Weight |
| Dimensions | Standard CENTUM CS 3000 Slot Dimensions |
| Operating Temp | 0 to +60 deg C |
| Power Consumption | System Backplane Powered |
| Number of Channels | 8 channels |
| Signal Input Types | 4-20 mA DC, 1-5 V DC, Thermocouple, RTD |
| A/D Conversion Resolution | 16-bit |
| Measurement Accuracy | +/-0.1% of full scale |
| Input Impedance (Power ON) | 250 ohm (current), 1 Mohm (voltage) |
| Input Resistance (Power OFF) | >=500 kohm (current), >=340 kohm (voltage) |
| Input Step Response Time | 100 ms |
4-20 mA HART Loop Protocol & Channel Isolation Characteristics
The NFA841 module features 16-bit A/D conversion stages tuned for precision process measurement, maintaining step response recovery times within 100 ms for analog inputs. Channel isolation barriers isolate the internal DCS backplane electronics from field-side electrical surges and ground loops. When configured for 4-20 mA loop processing, the module maintains an input impedance of 250 ohm during powered operation, transitioning to a high-impedance state (>=500 kohm) under unpowered conditions to preserve loop integrity across connected field devices.
Frequently Asked Questions
Q: What happens to the input loop impedance of the NFA841-S00/A4S00 when main power is removed?
A: Upon loss of power, the current input resistance increases from the nominal 250 ohm operational state to >=500 kohm, protecting connected field transmitter loops against ungrounded shorting risks.
Q: What is the step response execution speed of the module when acquiring analog input transitions?
A: The analog input stage processes full-scale step changes within 100 ms to provide rapid updates to the CENTUM CS 3000 controller backplane.
Q: Does the NFA841-S00/A4S00 support field temperature sensors directly?
A: Yes, depending on hardware channel configuration, the module directly conditions input inputs from thermocouple and RTD sensors as well as standard 4-20 mA DC and 1-5 V DC signals.
Field Installation Guidelines
- Insert the NFA841-S00/A4S00 module vertically into the designated I/O slot of the CENTUM CS 3000 node unit until the locking lever fully engages.
- Secure signal wiring to the terminal block assembly, ensuring terminal screws are torqued according to Yokogawa enclosure specifications.
- Terminate signal cable shields at a central grounding point to prevent circulating current loops across the analog signal channels.
- Separate low-voltage analog signal lines (1-5 V DC, RTD, Thermocouple) from high-voltage AC power distribution conduits to reduce induced field noise.
- Ensure cabinet ventilation meets thermal clearance requirements to maintain ambient operating conditions within standard limits.
Yokogawa NFA841-S00/A4S00 CENTUM CS 3000 Analog Input Module
Yokogawa NFA841-S00/A4S00 CENTUM CS 3000 Analog Input Module
The Yokogawa NFA841-S00/A4S00, also cataloged as the NFA841 Analog Input Module, operates as a dedicated hardware component for 8-channel analog signal acquisition and digitization within Yokogawa CENTUM CS 3000 DCS platforms. It conditions incoming field process signals—including 4-20 mA DC, 1-5 V DC, thermocouple, and RTD inputs—for direct internal controller processing and backplane distribution.
Suffix Breakdown & Model Matrix
The NFA841 model structure incorporates specific suffix coding to designate functional hardware variations and terminal connection options:
- NFA841: Base Model Designation (8-channel analog input module architecture)
- -S: Standard Signal Type/Execution Specification
- 00: Standard Hardware/Functionality Option Code
- /A4S00: Terminal Block Assembly Variant Code (Integrated pressure clamp/screw terminal connection configuration)
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | NFA841-S00/A4S00 |
| Brand | Yokogawa |
| Origin | Japan |
| Weight | Standard DCS Module Weight |
| Dimensions | Standard CENTUM CS 3000 Slot Dimensions |
| Operating Temp | 0 to +60 deg C |
| Power Consumption | System Backplane Powered |
| Number of Channels | 8 channels |
| Signal Input Types | 4-20 mA DC, 1-5 V DC, Thermocouple, RTD |
| A/D Conversion Resolution | 16-bit |
| Measurement Accuracy | +/-0.1% of full scale |
| Input Impedance (Power ON) | 250 ohm (current), 1 Mohm (voltage) |
| Input Resistance (Power OFF) | >=500 kohm (current), >=340 kohm (voltage) |
| Input Step Response Time | 100 ms |
4-20 mA HART Loop Protocol & Channel Isolation Characteristics
The NFA841 module features 16-bit A/D conversion stages tuned for precision process measurement, maintaining step response recovery times within 100 ms for analog inputs. Channel isolation barriers isolate the internal DCS backplane electronics from field-side electrical surges and ground loops. When configured for 4-20 mA loop processing, the module maintains an input impedance of 250 ohm during powered operation, transitioning to a high-impedance state (>=500 kohm) under unpowered conditions to preserve loop integrity across connected field devices.
Frequently Asked Questions
Q: What happens to the input loop impedance of the NFA841-S00/A4S00 when main power is removed?
A: Upon loss of power, the current input resistance increases from the nominal 250 ohm operational state to >=500 kohm, protecting connected field transmitter loops against ungrounded shorting risks.
Q: What is the step response execution speed of the module when acquiring analog input transitions?
A: The analog input stage processes full-scale step changes within 100 ms to provide rapid updates to the CENTUM CS 3000 controller backplane.
Q: Does the NFA841-S00/A4S00 support field temperature sensors directly?
A: Yes, depending on hardware channel configuration, the module directly conditions input inputs from thermocouple and RTD sensors as well as standard 4-20 mA DC and 1-5 V DC signals.
Field Installation Guidelines
- Insert the NFA841-S00/A4S00 module vertically into the designated I/O slot of the CENTUM CS 3000 node unit until the locking lever fully engages.
- Secure signal wiring to the terminal block assembly, ensuring terminal screws are torqued according to Yokogawa enclosure specifications.
- Terminate signal cable shields at a central grounding point to prevent circulating current loops across the analog signal channels.
- Separate low-voltage analog signal lines (1-5 V DC, RTD, Thermocouple) from high-voltage AC power distribution conduits to reduce induced field noise.
- Ensure cabinet ventilation meets thermal clearance requirements to maintain ambient operating conditions within standard limits.
