Yokogawa MDK2-S1 I/O Module
The Yokogawa MDK2-S1, also cataloged as the MDK2 I/O Module, operates as a dedicated hardware component for dual-directional serial protocol conversion and signal level translation within Yokogawa industrial control systems. The module bridges RS232C and RS485 communication pathways while applying galvanic isolation across signal lines to prevent ground potential variations from degrading data integrity.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | MDK2-S1 |
| Brand | Yokogawa |
| Origin | Japan |
| Weight | 0.6 kg |
| Dimensions | 43 x 2 x 32 cm |
| Operating Temp | 0 deg C to +55 deg C |
| Power Consumption | Standard backplane power allocation |
| Product Type | I/O Module / Dual Directional Converter |
| Communication Protocols | RS232C, RS485 |
| Signal Protection | Electrical Isolation |
4-20 mA HART & Fieldbus Communication Protocols
The Yokogawa MDK2-S1 module leverages channel-to-channel isolation circuits to decouple field-side voltage spikes, common-mode noise, and differential ground loops from central control logic. Active drive control dynamically manages signal transmission timing between RS232C point-to-point topologies and RS485 multi-drop networks, ensuring deterministic data transfer without host processing latency or signal attenuation across extended field cabling distances.
Frequently Asked Questions
Q: What physical installation form factor does the MDK2-S1 utilize within a cabinet panel?
A: The MDK2-S1 features a direct plug-in design, allowing insertion and locking onto compatible system subracks or baseplates without requiring manual wire-by-wire disconnection during replacement.
Q: How does the module handle signal level conversion between RS232C and RS485 transceivers?
A: Internal converter hardware automatically translates single-ended RS232C bipolar voltage signals into differential RS485 voltage levels while maintaining galvanic isolation across the communications barrier.
Field Installation Guidelines
- Ensure panel backplane power is turned off before inserting the module into its mounting slot to prevent pin arcing on the connector interface.
- Route RS232C and RS485 communication cables through dedicated trunking, maintaining a minimum 200 mm clearance from three-phase AC power conductors and motor drives.
- Connect signal cable shielding to a dedicated single-point earth ground bus bar inside the enclosure to suppress electro-magnetic interference (EMI).
- Verify field wiring terminations conform to the maximum segment length limits specified for RS485 differential signals (typically 1200 meters) and apply proper bus termination resistors where required.
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 MDK2-S1 I/O Module
Yokogawa MDK2-S1 I/O Module
The Yokogawa MDK2-S1, also cataloged as the MDK2 I/O Module, operates as a dedicated hardware component for dual-directional serial protocol conversion and signal level translation within Yokogawa industrial control systems. The module bridges RS232C and RS485 communication pathways while applying galvanic isolation across signal lines to prevent ground potential variations from degrading data integrity.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | MDK2-S1 |
| Brand | Yokogawa |
| Origin | Japan |
| Weight | 0.6 kg |
| Dimensions | 43 x 2 x 32 cm |
| Operating Temp | 0 deg C to +55 deg C |
| Power Consumption | Standard backplane power allocation |
| Product Type | I/O Module / Dual Directional Converter |
| Communication Protocols | RS232C, RS485 |
| Signal Protection | Electrical Isolation |
4-20 mA HART & Fieldbus Communication Protocols
The Yokogawa MDK2-S1 module leverages channel-to-channel isolation circuits to decouple field-side voltage spikes, common-mode noise, and differential ground loops from central control logic. Active drive control dynamically manages signal transmission timing between RS232C point-to-point topologies and RS485 multi-drop networks, ensuring deterministic data transfer without host processing latency or signal attenuation across extended field cabling distances.
Frequently Asked Questions
Q: What physical installation form factor does the MDK2-S1 utilize within a cabinet panel?
A: The MDK2-S1 features a direct plug-in design, allowing insertion and locking onto compatible system subracks or baseplates without requiring manual wire-by-wire disconnection during replacement.
Q: How does the module handle signal level conversion between RS232C and RS485 transceivers?
A: Internal converter hardware automatically translates single-ended RS232C bipolar voltage signals into differential RS485 voltage levels while maintaining galvanic isolation across the communications barrier.
Field Installation Guidelines
- Ensure panel backplane power is turned off before inserting the module into its mounting slot to prevent pin arcing on the connector interface.
- Route RS232C and RS485 communication cables through dedicated trunking, maintaining a minimum 200 mm clearance from three-phase AC power conductors and motor drives.
- Connect signal cable shielding to a dedicated single-point earth ground bus bar inside the enclosure to suppress electro-magnetic interference (EMI).
- Verify field wiring terminations conform to the maximum segment length limits specified for RS485 differential signals (typically 1200 meters) and apply proper bus termination resistors where required.
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.
