1. Single-Lane (x1) PCI-Express with throughput up to 5.0 / 2.5Gbps
  2. Fully compliant with PCI-Express Base Specification Rev 2.0
  3. Top serial transmission performance up to 921.6 Kbps baud rate
  4. FIFO 256 Bytes, 15 KV ESD protections on board
  5. H/W, S/W automate flow control supported
  6. RS-232/422/485 mode selectable by DIP switch setting
  7. Each port supports 5V or 12V power output by DIP switch setting
MEC-COM-M334 is a serial communication card for embedded PC. The card follows the Mini PCI-e standard which is complaint with PCI Express x 1 classification and small form factor (30.00 x 50.95 mm). This board fits in any host computer that has Mini PCI-e card slots.
Top Performance
MEC-COM-M334 has 4 RS-232/422/485 serial ports, each individual port supports 921.6 Kbps baud rate. The combination features 15KV ESD protection, FIFO 256 Bytes, HW/SW automated flow control and extended operating temperature which enhances the board’s reliability and performance.
High Usability
MEC-COM-M334 is designed with flexibilities for many different applications. The Serial RS- 232/422/485 mode and power output can be configured by DIP switches. The accessories (bracket, connection / power input cable) are included in the standard package.


General PCI-Express Revision PCI-Express Base Specification Rev 2.0
Electromechanical Revision
PCI-Express Mini Card Electromechanical
Rev. 2.0
Hardware Controllers XR17V354 (16C550C compatible)
  Bus Single-Lane (x1) PCI-Express with throughput up to 5.0 / 2.5Gbps
Interface (Connector) RS-232 / 422 / 485 4 (DB9 male)
Serial Line Protection ESD Protection 15 KV on board
Serial Port Power  Voltage Select 5V or 12V
Performance Baud Rate Asynchronous baud rates up to 921.6 Kbps 
Dimensions Width x Length (mm) 30.00 x 50.95
Serial Communication Parameters Data Bits 5, 6, 7, 8
  Stop Bits 1, 1.5, 2
  Parity No Parity bit
Odd Parity bit
Even Parity bit
Parity bit forced to 1
Parity bit forced to 0
  Flow Control RTS/CTS, XON/XOFF
Environmental Limits Operating Temperature -40°C ~ +85°C
  Storage Temperature  -40°C ~ +95°C
  Humidity 5% ~ 95%
Serial Signals RS-232 TXD, RXD, RTS, CTS, DTR, DSR, DCD, GND, RI
  RS-422 TXD+, TXD-, RXD+, RXD-
  RS-485 DATA+, DATA-
Regulatory Approvals EMC CE, FCC
  EMI  EN 55022, EN61000-3-2, EN61000-3-3,
FCC Part 15 Subpart B Class B
  EMS En 55024, IEC 61000-4-2, IEC 61000-4-3,IEC 61000-4-4, IEC 61000-4-5, IEC 61000-4-6,IEC 61000-4-8, IEC 61000-4-11
Driver Support Operating Systems Win 2000, Win XP, Win Vista, Win 7,
Win 8, Win 10 
Power Requirement Power Consumption 645mA@3.3V
Reliability MBTF 1,631,268 hr
  Warranty  3 years 


Model No. Description
MEC-COM-M334 Mini PCI-e 4-port RS-232/422/485 serial board with power input


File Name Date Size
Datasheet_MEC-COM-M334 V1.1.pdf 14-05-2020 713.7KB