METSO S422737 Analog Output Board (AO Module)

This model usually plays a crucial role in the distributed control system (DCS) and process automation hardware of Metso (now part of Valmet).

1. Product Description

The METSO S422737 is an industrial-grade analog output module, which is a core I/O component of Metso’s automation system.

This module is mainly used to convert the digital control signals within the DCS system into standard analog current signals (such as 4-20 mA),

thereby driving on-site regulating valves, frequency converters, servo mechanisms, or other proportional control devices. Its design meets the high reliability and accuracy requirements of heavy industrial environments.

2. Technical Data Sheet

Model: S422737

Product type: Analog Output Board (AO Module)

Number of channels: Usually 8 channels or 16 channels (depending on the specific sub-model configuration).

Output signal range: 0–20 mA or 4–20 mA (configurable by software).

Resolution: 12-bit to 16-bit (ensuring extremely smooth control curves).

Load impedance: Maximum supported is 600–750 ohms.

Isolation: There is current isolation protection between the channel and the system bus, preventing electromagnetic interference from the field from damaging the main controller.

Manufacturing standard: Meets industrial electrical certifications such as CE and CSA.

3. Related Models / Components

The S422737 module is typically integrated into the following systems:

S420154: Corresponding I/O backplane (slot).

S422736: The analog input module (AI Module) that is used in conjunction with it.

S422740: Possible redundant power module or bus conversion module.

TCU 41 / TIU 61: Terminal conversion unit for signal wiring.

4. Application Cases

Paper machine control: In the Valmet DNA automation system, it is used to control the dilution water regulating valve or the speed control of the paper winding machine.

Energy and Boiler: The air/fuel ratio control valve of the combustion system is adjusted to achieve precise combustion management.

Mining processing: Level regulating valves used to control the liquid level in the flotation tanks or chemical agent adding pumps in the beneficiation process (controlled by frequency converters).

Water treatment: Controls the flow output of large pumps or the actuators of the dosing system.

5. Product Advantages and Features

High precision output: Extremely low temperature drift and non-linear error, ensuring the stability of the process.

Powerful fault diagnosis: The on-board LED status indicator can display the module’s health status and supports remote monitoring of faults such as output loop breakage through software.

Redundant architecture compatibility: Supports redundant configuration. Even if a single module fails, the backup module can quickly take over, ensuring that the critical production line does not stop.

Resistant to harsh environments: The design has been strengthened to withstand dusty, hot and humid conditions commonly found in industries such as papermaking and mining.

6. Other Models in the Series

In the S4 series I/O hardware of Metso/Volmet, the common models within the same series include:

S422735: Digital Input Module (DI).

S422738: Digital Output Module (DO).

S422739: Temperature/Thermal Resistance Input Module (RTD).

PDP 401: Distributed Processing Module, used to manage all the I/O of the S4 series mentioned above.