USB to Serial TTL stops working after 20 minutes - Page 1
Forum section: electronics / projects

author: blueagle91
author_rank: Newbie
timestamp: October 29, 2017, 06:14:44 pm
content: Hello,So ive made a simple converter from RS422 to TTL using MAX485 and feeding that to one of those chinesium Prolific dongle things, USB to TTL.Everything works perfectly, im feeding data to PC only, and after 20 minutes it just stops. No data transfer. From source data is still going, MAX485 still converts levels as it should but that Prolific converter stops.Any idea? Windows maybe?Im using Windows 8.1, laptop no other USB devices connected, except internal laptop devices. Running from charger, and prolific receives its power supply over USB, as well as MAX485.What am i missing?

author: alsetalokin4017
author_rank: Super Contributor
timestamp: October 29, 2017, 06:37:42 pm
content: Does it work again if you exit Windows, reboot, restart Windows?

author: voltsandjolts
author_rank: Unknown
timestamp: October 29, 2017, 06:39:25 pm
content: I've had similar issue with Prolific and Win10, data to PC stopped while the data out of PC was still making it through.Swapped out to genuine FTDI and problem solved.Edit: I do believe that Prolific products are generally good quality, I just didn't have time to nail down this problem. It may have been a fake chip but it was a costly converter that I was using. So, dunno.

author: stj
author_rank: Super Contributor
timestamp: October 29, 2017, 06:44:15 pm
content: simple test would be a linux live dvd with a terminal program to display the incomming data.minicom for example.

author: texaspyro
author_rank: Super Contributor
timestamp: October 29, 2017, 06:59:02 pm
content: I suspect a driver issue. I had a bunch of Chinese Prolific adapters stop working on Windoze XP after I installed a couple of packages (Arduino IDE and TL866). The USB dongles started sending garbage data after a day or so. Rolling back the dongle driver to an earlier version fixed it. I suspect Prolific snuck some anti-clone code into their drivers.

author: blueagle91
author_rank: Newbie
timestamp: October 29, 2017, 07:43:28 pm
content: Hmmm, yeah im using some drivers which work with the cheap chinese one. I turned off the ability for laptop to shut down the USB hub after being still in power management. Tomorrow ill try if that is the case, if not, i have FTDI FT232BL so id have to make a PCB for it and hope it works normally.Im from Serbia, and here there is a sane (i think its the proper word) it says: I`m not reach enough to buy cheap stuff!

author: ajb
author_rank: Super Contributor
timestamp: October 29, 2017, 08:07:20 pm
content: What are you using to receive data from the adapter on the PC? Are you sure that the USB IC is no longer sending data to the PC, or could it be that the software that is receiving the data is the problem?Does closing the connection to the USB IC in the software and reopening it make it work again? Does closing the software and restarting it make it work again?Roughly how much data will your device have sent to the PC after 20 minutes?

author: blueagle91
author_rank: Newbie
timestamp: October 29, 2017, 08:42:05 pm
content: Yes definetly software is not a problem, only unplugging and plugging adapter resumes operations. Restarting software does not help, reopening port does not help. Its like adapter goes to sleep