Configured for optical extension‑base communication in HC900 and ControlEdge platforms, the Honeywell 2MLR-DBSF (2MLR-DBSF fiber interface module) provides physical optical signaling between distributed I/O bases using multi‑mode fiber and LC connectors.
Hardware Specifications
Parameter
Specification
Model
2MLR-DBSF
Brand
Honeywell
Origin
USA
Media Type
Optical
Max Distance
2 km (multi‑mode fiber)
Cable Specification
62.5/125 multi‑mode fiber
Connector Type
LC (Lucent Connector)
Return Loss
> 45 dB
Loader Connection
Extension drive USB
Station Range
1 to 31 (other numbers generate error)
Install Position
CPU parts (CPU0 connector) in extension base
Weight
99 g
4-20 mA HART Loop Protocol & Channel Isolation Behavior
Although the module handles optical communication rather than analog loops, its fiber‑based signaling architecture prevents electrical coupling between extension bases. Optical isolation eliminates ground‑loop interference and ensures deterministic backplane communication across long distances. The LC multi‑mode interface maintains stable attenuation characteristics, preventing cross‑talk between adjacent optical channels.
Frequently Asked Questions
Q: Can the 2MLR-DBSF be inserted or removed while the extension base is powered? A: No. The extension base must be fully de‑energized before module insertion or removal to avoid communication faults.
Q: What happens if a station number outside 1 to 31 is assigned? A: The system flags an error and prevents initialization of the extension link.
Q: Does fiber length affect communication timing? A: Within the 2 km limit, timing remains deterministic. Excessive length or incorrect fiber type may increase attenuation.
Field Installation Guidelines
Use 62.5/125 multi‑mode fiber exclusively to maintain correct optical attenuation. Ensure LC connectors are fully seated and free of dust; contamination can significantly reduce return loss. Route fiber cables separately from copper conductors to avoid mechanical stress. Maintain minimum bend radius as specified for multi‑mode fiber to prevent signal degradation. Confirm correct station numbering before energizing the extension base.
