M.2 4-port Isolated RS-485 serial

  • Description
  • Specifications
  • Ordering Guide
  • Optional Accessories

The M.2-ICM485 family of cards feature high performance 16C950-class UARTs. Available in 4-port (M.2-ICM485-4), 2-port (M.2-ICM485-2) and 1-port (M.2-ICM485-1) versions, each port is capable of communication speeds as high as 3Mbps and has 128-byte deep transmit and receive FIFOs. Large FIFOs protect against data loss in multitasking operating systems, reduce CPU utilization, and improve data throughput, while reducing or eliminating inter-character or inter-packet pauses. The advanced integrated circuit with pre-scalar supports a wide variety of custom baud rates, and any rates not otherwise achievable can be supported via a custom factory-installed crystal oscillator (up to 12Mbps!).

Tru-Iso™ port-to-port and port-to-PC isolation provides a robust solution to common signal level and grounding issues when using long cables to connect computers and other powered devices – up to 500V of difference between pins and adjacent ports and 1500V between each port and the host computer.

Communication is possible either with custom application software, with off-the-shelf applications (such as HyperTerminal), or with provided samples and utilities, including WinRISC™ (“Windows Really Incredibly Simple Communication).

The serial ports on the device are accessed using a low-profile, latching, 5-pin Hirose connector. Optional breakout cables are available, and bring each port connection to a panel-mountable DB9-M connector.

Interface M.2 2260/2280 with B & M key
Number of serial ports 4, 2 or 1 port
Protocols RS-485
Maximum baud rate Up to 3M baud
Advanced-prescaler allows a wide variety of unusual baud rates to be achieved
Up to 12Mbps via custom crystal option
UARTs Quad 16C950
FIFO 128-byte FIFO for each transmit & receive buffer
Isolation Port-to-PC: 1500V peak (AC or DC)
Port-to-port: 500V peak (AC or DC)
Power required +3.3VDC @ 1.6W (typical)
Operating temperature -40ºC to +85ºC
Operating humidity 5% to 95% noncondensing
ESD Protection ±15kV on all signal pins (IEC 61000)
Weight 6.4g


Model Description
M.2-ICM485-4 M.2 4-port Isolated RS-485 serial
M.2-ICM485-2 M.2 2-port Isolated RS-485 serial
M.2-ICM485-1 M.2 1-port Isolated RS-485 serial


Model Description
CAB-M.2-ICM4S Four port cable kit for M.2-ICM485-4. M.2-ICM422-4
CAB-M.2-ICM2S Two port cable kit for M.2-ICM485-2. M.2-ICM422-2
CAB-M.2-ICM1S One port cable kit for M.2-ICM485-1,. M.2-ICM422-1
M.2-HDW-KIT2 2mm mounting hardware kit
M.2-HDW-KIT2.5 2.5mm mounting hardware kit