PRODUCTS > RS-232 to RS-422/485 > SER-4485-SI-M


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  • SER-4485-SI-M
  • SER-4485-SI-M
  • SER-4485-SI-M
SER-4485-SI-M - RS-232/485 to 4-Port RS-485 Hub, Splitter and Repeater Isolated 4 Channels RS-485 Hub/Splitter/Repeater, with Optical Isolation and Surge Protection, Failure Warning, Compact Palm-size metal case with DIN Rail Bracket

The USB-4485-SI-M is an industrial-grade 4-port RS-485 hub, splitter and repeater, with optical isolation of 3000 Volt and ESD protection of 15000 Volt. This RS-485 hub is designed to expand a RS-485 channel in the RS-485 network to four RS-485 channels. The RS-485 hub has one RS-232/RS-485 upstream input port and four downstream RS-485 output ports. Data received from the input channel will be simultaneously multicasting to all the four downstream channels. Data received from the downstream RS-485 ports is forwarded back to the upstream port only, and it is not sending to any other RS-485 ports in the node. When any RS-485 channel has incorrect signals or reverse wire connection, the error LED of that specific channel will light on for failure warning. It is very easy to locate the failed RS-485 channel. The failed port will be isolated automatically to prevent interference to other RS-485 channel in the node, to ensure normal operation of other RS-485 ports in the loop.


  • Industrial-grade 4 channels RS-485 Hub/Splitter/Repeater with rugged metal case

  • Input (upstream): 1 RS-485 Channel. Signals: Data+, Data-, TxD, RxD, GND

  • Output (downstream): 4 RS-485 Channels. Signals: Data+, Data-

  • Supports option for RS-232 and RS-485 dual input interface

  • Converts RS-232 port to 4 channels half-duplex RS-485 with automatic transmit and receive controls

  • Electrical isolation up to 3000VDC in between RS-485 upstream port and four RS-485 downstream ports to protect RS-485 devices

  • 600W surge protection circuit on all RS-485 bus

  • RS-485 port protected with surge protection of 15KV

  • Provides failure warning when reverse connection or incorrect signals detected

  • Failed RS-485 port easily detected and located.

  • Protected circuit for four RS-485 downstream ports to isolate breakdown channel automatically to avoid interference to other RS-485 ports

  • LEDs for power, communication and error status indication

  • Includes 12VDC power adapter with locking screw terminal for reliable connection

  • DC or AC 9V to 48V power input; reverse polarity input protection

  • Supports transmission data rate from 300 bps up to 230.4 Kbps

  • LEDs of power, TxD and RxD, Error for easy port monitoring and diagnostics

  • SECC metal chassis with DIN rail brackets

  • No driver installation required. Supports all operating systems.


Serial Interface
Input (upstream) 1 RS-232 channel: Data+, Data-;
or 1 RS-485 channel: TxD, RxD, GND
Output (downstream) 4 RS-485 channels: Data+, Data-
Number of Ports 4 RS-485 ports
Connectors 6-pin terminal block for upstream
10-pin terminal block for downstream
Serial Line Protection
ESD Protection 15KV
Optical Isolation 3000V DC on CH1 to CH4
2-way isolation
Serial Port Speed
Baud rate 300 bps to 230400 bps
Serial Communication Parameters
Data Bits 5, 6, 7, 8
Stop Bits 1, 1.5, 2
Parity None, Even, Odd, Space, Mark
Flow Control RTS/CTS, XON/XOFF
Serial Signals
RS-485-2 wire Data- (A), Data+ (B), GND
Automatic RS-485 transmit and receive control
Driver Support
OS No driver installation required
Works in all types of operation systems
Power Supply
Input Self-powered
Power adapter of 12 VDC, 2A.terminal type with screws
Range of AC or DC input from +9 VDC to +48 VDC
Chassis SECC metal chassis with DIN rail bracket
Operating Temperature 0 to 55 °C (32 to 131 °F)
Operating Humidity 5 to 95% RH
Storage Temperature -20 to 75 °C (-4 to 167 °F)
Safety Approvals CE, FCC