Only thing is the USB connection is not very tight, I just loop an elastic around my usb cable and the adaptor to prevent from sliding out. I have a long 15 foot USB cable between the laptop and the adapter so that I can sit comfortably away from the equipment and still do my programming. This unit has not failed me once and I carry it with me ALL THE TIME. I did a lot of research prior to buying that because I often connect to Cisco devices via Console. I purchased one of those a few years ago after I had to part way with my Dell D610 with winXP.

The Prolific chips are just emulators and only work about 75% of the time. This is because it has an FTDI chip, so it has a real serial processor, as opposed to a lot of the other brands/models, which use a Prolific chip. Keyspan USA-19HS is the only thing I've ever been able to get to work with all of the devices we use (Allen Bradley and Parker PLCs, shipping scales, network equipment, the list goes on). In the end, though, the guys who worked on those systems just kept an old D610 around running XP and used it exclusively for programming those older systems. There was (is?) also the 'E-Legacy Extender' for Dell Latitude laptops that provided a real hardware serial port as opposed to a USB version. We had the best luck with the Keyspan USA-19HS adapters, but there is just some programming software out there that can't fathom a port not named COM1 at $3F8 or COM2 at $2F8. I worked in that industry for a while as well. Most of the time on newer equipment they work fine, if your serial device is expecting to see all of the older handshaking business that happened with serial than it may not work correctly.

The only time I have ever experienced any issues was when I was dealing with very dedicated machinery (like a Allen-Bradley PLC, or a old Simplex fire alarm system).

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