M.2 COM-4SM Series of 2 & 4 Port RS-232 / 422 / 485 M.2 Cards
The M.2-COM-4SM family of 6 cards feature high performance 16C950-class UARTs. Available in 4-port and 2-port versions of RS-232 only (M.2-COM232-2/4); RS-422/485 (M.2-COM2/4S) and RS-232/422/485 (M.2-COM-2/4SM).
Each port is capable of communication speeds up to 921.6kbps in RS-232 (differential modes support 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 10Mbps!).
RS-232, RS-422, or RS-485 can be software selected, per port, and the selection is stored in non-volatile memory for future use. If you don’t need that much flexibility you can order versions with only RS422/485 or even pure RS232. The RS232 ports provided by the card are 100% compatible with every other industry-standard serial COM device, supporting TX, RX, RTS, and CTS. RS422 mode uses the same transceivers as the RS-485 specification, allowing perfect 4-wire RS-422 and RS-485 compatibility – and the device supports full-duplex RS-485 4-wire.
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, 6-pin Hirose connector. Optional breakout cables are available, and bring each port connection to a panel-mountable DB9-M connector.