Dev.ser for 485 serial ports


I have a moxa serial card with 8 485 serial ports, im using Dev.ser to drive these ports, but all i get is the Tx led flash when i send data, im not receiving anything, im directly connecting port 1 to port 2 of the same card just for testing… is Dev.ser capable of driving 485 ports?

Is there any generic driver for 485 like Dev.ser ?


There are various ways of handling 485 and it would be hard ( not impossible ) to do a generic diver for 485. The best card will handle 485 totally in hardware.

If it doesn’t you might to deal with it by software which is painfull, or you write your own driver. Do a search on this topic, this has been discuss many time in the past.

Thank you for your reply, i did search for 485 and qnx with no success on this forum but i’ll try again .

Serial multiport cards are:

  • “dumb” (non-intelligent) - they are managed in QNX4 in a standard manner (address/irq) as standard Ser1 and Ser2 (3F8,4 2F8,3… Ser3 e.g. 3E8,5 Ser4 e.g. 3E8,7…), you must set addresses/irqs by manner of HW jumpers or some newer cards had MS-DOS utility diskette to set the individual port parameters,
  • intelligent - they have own processor and require driver for QNX4. I know that CTI once made Intellicon ISA multiport cards with QNX4 drivers.

I succeeded only with ISA multiport cards under QNX4.