The telecontrol channel transmits remote signaling, telemetry, and remote control messages at a low rate, but a bit error may cause status misjudgment or even refusal to move. Optical fiber transformation cannot be designed just as long as it is passed. The following three points are recommended to be checked one by one during the program review.
Determine the interface form first and then select the conversion device
Most of the remote control devices in the station retain RS485 or 232 ports. When switching to optical fiber, it is better to choose a data optical transceiver with transparent transmission instead of a gateway for protocol conversion to reduce fault links. Point-to-point channels are available2-way bidirectional RS485 data optical terminalCarrying two main and backup links; when the number of channels is large, the rack will be installed for centralized power supply and centralized maintenance.
Delay and optical power must be calculated
The propagation delay of optical fiber is about 5μs/km, and the link of 100 kilometers is only half a millisecond. What really affects the end-to-end indicators is the device conversion and retransmission mechanism. When selecting, give priority to the transparent transmission delay parameters. The optical power is estimated to be about 0.35dB/km in 1310nm single mode. After adding jumper and splicing losses, it is recommended to leave a margin of about 3dB at the receiving end; for short-distance channels, such asSFP 100M single mode dual fiber 20KM optical moduleThat's it. If the mileage exceeds the mileage, you need to change to a longer distance gear.
Redundant routing is more effective than multiple backup devices
- For dual-channel telecontrol, try to use different physical optical cables to avoid single points of failure caused by the same cable in the same trench;
- The power taken by the optical terminals on both sides belongs to different DC bus sections to prevent power loss along the way from taking away all channels;
- The pigtail should be left with enough space on the side of the distribution frame, so that the optical fiber will not be subject to tension when inspecting and moving equipment.
Go through the drawings according to these three points, and most omissions can be discovered during the review stage. EB-LINK's data optical transceivers and SFP modules are tested one by one before leaving the factory. Test records can be provided with the goods. To request specifications during the planning stage, please call 0755-83179002.