Honeywell 2MLR-DBST Twisted Pair Expansion Driver Module

Product Overview

The Honeywell 2MLR-DBST is an electrical expansion driver module using twisted pair (TP/CAT5) media for the MasterLogic-200R (ML200R) redundant PLC system. It enables high-speed, short-range communication between the main CPU rack and distributed I/O extension bases via standard CAT5 twisted pair cable. Supporting up to 31 extension stations with automatic address error detection, it provides a cost-effective, easy-to-wire solution for modular control architectures.

Key Specifications

• Product Type: Electrical Expansion Driver Module (UTP/CAT5)
• Series: MasterLogic-200R (Redundant)
• Communication Media: TP/CAT5 (Twisted Pair, Electrical)
• Max Transmission Distance: 100 meters between extension bases
• Station Number Range: 1–31 (Station 0 not allowed)
• Loader Connection: USB extension drive
• Installation Position: CPU0 connector on extension base
• Input Voltage: DC 24V
• Isolation: Galvanic isolation between main and remote bases
• Dimensions (W x H x D): 150 mm x 100 mm x 30 mm
• Weight: 0.1 kg (100 g)
• Operating Temperature: -20°C to +60°C
• Certifications: CE, UL508, CSA, TUV

Features & Benefits

• Standard CAT5 cabling — uses inexpensive, readily available twisted pair cable, reducing material cost by 70% compared to fiber optic solutions
• 100 meter range — ideal for control rooms where remote I/O racks are in adjacent rooms or within the same building
• 31 station capacity — supports up to 31 extension bases per main rack, enabling massive I/O expansion without additional CPUs
• Automatic address error detection — prevents configuration mistakes by detecting duplicate or invalid station addresses during startup
• USB loader connection — built-in USB port enables direct programming and diagnostics access to the expansion network without additional adapters
• Galvanic isolation — protects the main CPU rack from ground potential differences and electrical faults on remote bases

Typical Applications

• Building automation central plant to air handling unit (AHU) I/O
• Factory automation with I/O racks on the same production floor
• Water treatment plant control room to pump house (<100 m)
• Pharmaceutical packaging line control
• Food & beverage processing with clean electrical environments
• Any application requiring CPU redundancy without long-distance fiber

Installation Guide

1. Install in main rack — mount the 2MLR-DBST in the expansion driver slot of the ML200R main base (2MLR-M02P or 2MLR-M06P).
2. Install paired module in expansion base — mount a corresponding 2MLR-DBST in the CPU0 slot of each 2MLR-E08P or 2MLR-E12P expansion base.
3. Connect CAT5 cable — use standard shielded CAT5e or CAT6 cable to connect the main rack DBST to the expansion base DBST. Maximum length is 100 meters.
4. Set station address — use the rotary switches or SoftMaster to set a unique station address (1–31) for each expansion base.
5. Apply 24V power — connect DC 24V to the DBST power terminals.
6. Verify link status — check the LINK and RUN LEDs on both modules. A solid green LED indicates proper communication.

FAQ

Q: What is the difference between 2MLR-DBST and 2MLR-DBSF?
A: The 2MLR-DBST uses twisted pair (UTP/CAT5) for I/O expansion up to 100 meters. The 2MLR-DBSF uses fiber optic (FO) for expansion up to 15 km. Choose DBST for short-distance copper runs in clean environments; choose DBSF for long-distance or high-EMI applications.

Q: What is the difference between 2MLR-DBST and 2MLR-DBDF?
A: The 2MLR-DBST is a single-path expansion driver. The 2MLR-DBDF is a dual redundant expansion driver with fiber optic for fully redundant dual-ring configurations. For maximum availability, use DBDF in pairs.

Q: Can I use standard Ethernet switches with this module?
A: No. The 2MLR-DBST uses a proprietary high-speed serial protocol over CAT5 cable, not standard Ethernet. Do not connect to Ethernet switches or routers — doing so will cause communication failure.

Q: What CAT5 cable specification is required?
A: Use shielded CAT5e or CAT6 cable with a maximum length of 100 meters. Unshielded cable may experience EMI issues in industrial environments.

Selection Tips

• Select 2MLR-DBST when your remote I/O cabinet is within 100 meters and the electrical environment is clean (low VFD/welding interference).
• For >100 m or high-EMI, choose 2MLR-DBSF with fiber optic.
• Always use shielded CAT5e or CAT6 cable — unshielded cable is not recommended for industrial environments.
• Verify your total expansion base count does not exceed 31 stations per main rack.
• For fully redundant dual-ring architectures, pair the DBST with 2MLR-DBDF on the alternate path or upgrade to fiber.