Our PCMCIA Serial RS232 card has been tested succesfully with the following PLC's: Siemens (STEP7, MicroWIN), Allen Bradley (ControlLogix 5000, RSLogix 500, RSLinx), Mitsubishi (GX Developer). The card will not work with Allen Bradley 5/01, 5/02 or the DH port on a 5/03, no PCMCIA/serial card work with these PLC models, only a real standard internal serial port will work. --------------------------------------------