YF-504A RS485 Signal Amplifier Distributor has the function of intermediate amplification, which can convert 1-channel RS485 signal input into 4-channel RS485 signal output and extend the communication distance.
About this manual
The YF-504A RS485 signal amplifier/distributor expands a single RS485 input to four isolated outputs, each capable of driving up to 128 terminals for a total of 512 nodes. It supports unidirectional transmission and can extend communication distance up to 1200 m, with ports designed for anti‑static and lightning protection.
Installation requires a DC9‑12 V, 500 mA power supply, proper A/B wiring, and a 120 Ω termination resistor at the far end of each loop (only one resistor per loop). The package includes the distributor, power adapter, manual, certification, and four 120 Ω resistors. This manual is written in Chinese.
What's inside
- Product Overview
- Technical Specifications
- Installation Instructions
- Wiring Guidelines
- Power Requirements
- Accessories
Specifications
| RS485 input channels | 1 |
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| RS485 output channels | 4 |
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| Maximum communication distance per output | 1200 m |
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| Terminals per output | 128 |
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| Total supported nodes | 512 (4 × 128) |
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| Power input | DC9‑12 V, 500 mA |
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| Port protection | Anti‑static, lightning‑proof |
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| Termination resistor per loop | 120 Ω (one per loop) |
Frequently asked questions
How many RS485 terminals can each output support?
Each RS485 output can connect up to 128 terminals, allowing a maximum of 4 × 128 = 512 nodes.
What power supply is required for the YF-504A?
The device requires a DC power supply of 9 to 12 V with a current rating of 500 mA.
Do the RS485 ports need termination resistors?
Yes, a 120 Ω resistor must be placed at the far end of each RS485 loop, and only one resistor is allowed per loop.
What type of cable should be used for RS485 connections?
Shielded twisted‑pair cable must be used; using parallel wires will greatly reduce communication distance.