> -----Original Message----- > From: Chris Olson [mailto:chris_e_olson at yahoo.com] > Sent: Thursday, November 16, 2017 5:42 PM > To: CentOS Mailing List > Subject: [CentOS] USB Serial Ports > > We have several CentOS 6 systems that are used in various configurations > of test equipment. One of the primary functions of these systems is the > connectivity to serial ports of some operational systems that have serial > port control requirements. Lack of interface bus slots led us to the use > of USB connected serial ports on these CentOS 6 systems. > > We first used these USB connected serial ports in our RHEL 5 test equipment > systems. With RHEL 5, shut down and boot up of the systems would often > cause the serial ports to have a different driver name, even though we had > not changed the ports where the USB devices were plugged in. This caused > software access problems until we discovered what could be done using the > udev rules to lock in the driver names. > > This problem seems to have gone away in our newer systems with CentOS 6, > and we would like to make sure that it does not return. We are deploying > some of the systems and do not want to have software access issues in the > field where fixes are more difficult. We would like to know if there is > some underlying factor that has solved this problem for us. Any ideas on > what to check would be greatly appreciated. > I have no idea why it is working better under 6, but it is possible to use UDEV rules to force them to be at expected /dev/my_tty* locations using vendor_ID/device_ID/serial_number combinations. Once you figure that out, you should even be able to use the same (or at least similar) rules under 7. -- Even when this disclaimer is not here: I am not a contracting officer. I do not have authority to make or modify the terms of any contract.