Knowledge

There are many types of fiber optic transceivers, but the decision chain only has five steps. This article provides a layer-by-layer selection list based on speed, single and dual fibers, port combinations, wavelength pairing, and installation methods. You can basically lock in the model after asking questions.

The single-fiber optical transceiver relies on two wavelengths to transmit bidirectionally in the same optical fiber. If the A-end and B-end are mismatched, the link will not work. This article explains the principle of wavelength complementation, how to read the pairing mark, and the verification steps when replacing equipment.

Once there are too many links, bulk box-type optical fiber transceivers will become a burden for power distribution and management. This article talks about the value of a 14-slot rack, and how to judge how many links are worth switching from a box-based to a rack-based solution.

The number of electrical ports of an optical fiber transceiver determines how many terminals a device can carry. This article sorts out the applicable scenarios and bandwidth sharing algorithms of one optical and one electrical, one optical and two electrical, one optical and four electrical to one optical and eight electrical according to the point density, so as to avoid the waste of selecting too much or changing the machine when selecting too few.

Single-fiber and dual-fiber optical transceivers determine how many fibers the link occupies, how much the fiber core costs, and where the fault point is. This article compares the working principles, device costs, and operation and maintenance differences between the two solutions, and provides criteria for making decisions based on core resources.

The reason why 100M and Gigabit optical fiber transceivers cannot be mixed at will lies in the speed range. This article explains the differences between the two in terms of bandwidth, negotiation mechanism, and selection price, and provides a method to determine the rate based on terminal traffic to avoid the link being clearly connected but the service being rate-limited.

For the same 485 card, some sites have not been disconnected for many years, while others frequently report verification errors. The difference is often in the construction. This article discusses three key points: terminal resistor placement, hand-in-hand topology, and shielded single-ended grounding, and provides a reference for substation scenarios.

The card is plugged in, but the COM port is not visible in the system. This is the most frequently asked question after-sales consultation for serial port cards. This article gives a four-step troubleshooting sequence for identifying devices, handling COM number conflicts, and checking parameters and directions. Most of them can be solved by themselves.

When upgrading old cash registers and laboratory host machines, LPT parallel port printing and multi-channel serial port peripherals are real problems for the new platform. This article gives a card configuration plan based on three ideas: retaining parallel ports, completing multiple serial ports, and selecting parallel-serial combination cards.

Distance and interference are invisible bottlenecks in serial port networking transformation. This article explains how to determine whether the 485 bus is over-distance, and use a bidirectional 485 data optical transceiver to transparently extend the bus to the optical fiber bit by bit without changing the protocol or baud rate.