Description
1. At-A-Glance Executive Brief
- Model: MDW-45
- Brand: Westermo
- Part Type: Industrial RS-232 to RS-422/485 Serial Converter
- Lifecycle Status: Active / Industrial Support Tier
- System Compatibility: Legacy PLC serial ports, RTUs, and industrial automation networks
- Core Protocol: RS-232, RS-422, and RS-485 (2-wire or 4-wire bus)
2. Technical Introduction
Legacy field devices often rely on RS-232 serial ports that fail to communicate over the long distances or electrical noise common in heavy industrial facilities.
The Westermo MDW-45 acts as a heavy-duty industrial data converter, bridging RS-232 networks to RS-422 or RS-485 standards. It features total galvanic isolation, transient protection, and DIP-switch configuration, allowing control engineers to extend serial communication up to 1.2 kilometers while protecting sensitive automation hardware from ground loops and electrical surges.
- Best Suited For:
- Substation automation and railway trackside communication links
- Interfacing legacy PLC programming ports with remote SCADA networks
- Harsh industrial environments with severe electromagnetic interference (EMI)
3. Core Technical Specifications
| Parameter | Value |
| RS-232 Interface | 9-pin D-sub male (DTE) connector |
| RS-422/485 Interface | 4-position detachable screw terminal |
| Baud Rate | 300 bit/s to 115.2 kbit/s |
| Data Format | Selectable 9 to 12 bit (7 or 8 data bits, parity, 1 or 2 stop bits) |
| Galvanic Isolation | Total isolation between ports and power supply |
| Mounting Style | DIN-rail mounting with integral clip |
| Operating Temperature | -40 °C to +70 °C (-40 °F to +158 °F) |
4. Field Engineer’s Tech Notes
- Data Direction Control: While RS-485 data direction is normally governed by RS-232 handshaking lines (RTS/CTS), verify that the automatic turning time function is properly configured via DIP switches if your control software lacks hardware flow control.
- Line Termination and Fail-Safe biasing: Ensure proper termination resistors (typically 120 ohms) are engaged on the extreme ends of the RS-485 multi-drop bus using the internal DIP switches to eliminate signal reflections and data corruption during idle states.
5. Adaptive QA & Testing Protocol
Each unit undergoes serial loopback testing across full baud rate ranges from 300 bps to 115.2 kbps to verify bit error rates and packet integrity between the RS-232 and RS-422/485 ports. Technicians validate galvanic isolation breakdown thresholds, internal power supply regulation, and data LED switching responsiveness under simulated line traffic. Complete test logs and verification videos are available upon request prior to dispatch.
6. Buyer’s FAQ
- What operational condition is this converter supplied in?Inventory is maintained in factory-sealed New Surplus (NSFP) and rigorously bench-tested refurbished conditions, backed by a standard operational warranty.
- What is the standard shipping lead time for urgent site requirements?Standard stock orders dispatch within 1 to 2 business days via global priority couriers to prevent extended network downtime during unexpected hardware failures.
- Are there voltage variations available for power input?Yes, the unit is available in dedicated Low Voltage (LV) and High Voltage (HV) versions to accommodate standard DC or AC control cabinet power supplies.
