User manual for the FS-OLM-M PROFIBUS fiber optic link module, covering features, specifications, installation and troubleshooting.
The FS-OLM-M is an industrial‑grade PROFIBUS‑DP to fiber‑optic link converter produced by Four Star Electronics. It converts RS485 signals to optical signals for long‑distance, high‑speed communication in PROFIBUS, MPI and PPI networks.
The manual provides an overview of the module, its main applications, technical specifications, external connector layout, internal block diagram, wiring options, and a FAQ section that addresses common installation and troubleshooting questions. This manual is written in Chinese.
| Power supply voltage | 9‑40 VDC |
|---|---|
| Communication rate | 0‑12 Mbps (auto‑adaptive) |
| Maximum fiber distance (multimode) | 0‑4 km |
| Operating temperature | -40 °C to +85 °C |
| Dimensions (L×W×H) | 93 mm × 99 mm × 28 mm |
| Weight | 210 g |
| Fiber type (multimode) | 62.5/125 µm multimode |
| Wavelength | 1310 nm |
| Transmit optical power | -6 dBm |
| Receiver sensitivity | -18 dBm |
| RS485 surge protection | Ipp = 100 A (10/700 µs, 4 kV) |
| ESD protection | ±15 kV |
FS-OLM-M uses multimode fiber with a maximum transmission distance of 4 km, while FS-OLM‑S uses single‑mode fiber and can reach up to 12 km; all other functions are identical.
The local module stops receiving optical signals, a fault signal occupies the DP bus for about 350 ms and the corresponding fiber‑break indicator (CH1‑OFF or CH2‑OFF) lights up; the bus then resumes normal communication.