If it is an older APC UPS, that uses basic serial signaling, it's not actually a serial port, it's a criss-cross special serial cable that manages the control lines with DSR DTR CTS and so forth. these are very fussy cables that have to be exactly the right one or the UPS may just abruptly shut off. As far as USB serial cables go, the FTDI ones have always worked well for me,at least for applications that actually use the serial port for serial data On Wed, Jul 8, 2020, 8:14 AM H <agents at meddatainc.com> wrote: > I need to connect an older APS UPS unit to a machine running CentOS 7. > Unfortunately the UPS only has a serial port whereas the computer does not. > I am aware that there are USB-serial adapters but that the hardware or the > drivers might fall short of expectations. > > Does anyone have positive experience with such an adapter? Or, conversely, > would recommend avoid a particular adapter? > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos >