Fiber optic communication is utilized on Doran’s intrinsically safe indicators (models 8100IS and 8200IS) to ensure safe data transmission in hazardous environments. Rather than electrical signals, this method uses light sent through fiber optic cable to carry information, meaning there is no electrical current traveling between the scale and the outside devices. In explosive or flammable atmospheres, this is a critical safety feature – fiber optic lines cannot spark or cause ignition. With the fiber optic option, the scale can transmit weight data out of a Class I/II/III Div 1 hazardous area to a safe area without the need for heavy conduit or isolation barriers typically required for copper cables.
KEY PERFORMANCE FEATURES INCLUDE
Intrinsically Safe Connectivity
The 8100IS and 8200IS indicators come standard with dual fiber optic ports for data communication. These ports provide a full duplex (bi-directional) serial link over light, effectively replacing an RS-232 connection with an optical link. Because no electrical energy passes through the fiber, it meets the stringent requirements for intrinsic safety in hazardous (explosion-risk) zones. Operators can gather data from or send commands to the scale without any risk of igniting vapors or dust.
Long Distance, High Integrity Signal
Fiber optic communication not only enhances safety but also performance. It can reliably carry the signal over long distances (up to 1000 feet) without repeaters, far exceeding typical copper serial cable limits. The optical signal is immune to electromagnetic interference and radio-frequency noise, which is ideal in facilities with heavy machinery or RF equipment. This ensures that even in environments with high electrical noise, the weight data travels intact and error-free to the receiving system.
Simplified Hazardous-Area Installation
In an intrinsic safety scenario, running standard cables usually means encasing them in conduit and using explosion-proof fittings – a costly and time-consuming installation. Fiber optics simplifies this: the lightweight fiber cable can be run through the area without special conduit, significantly reducing installation and maintenance efforts. The absence of metal wiring removes the need for complex grounding or shielding practices as well.
Safe Area Interface
To use the fiber link with standard equipment, Doran provides a fiber optic interface converter located in the safe area. This converter takes the light signal from the fiber and converts it back to a conventional RS-232 serial output (or other needed interface) that can plug into computers, printers, or PLCs outside the hazardous zone. In practice, the intrinsically safe scale in the hazardous area connects via fiber to the converter in the non-hazardous area, and from there to your data collection software or devices. This allows seamless integration of hazardous-area scales into your normal operations and data streams, with full safety compliance.