I am using a USB-to-Serial converter for Docklight Monitoring Mode (passive RS232 monitoring). The computer randomly reboots / shows a stop error / “Blue Screen of Death” / BSOD. How do I fix this?

I am using a USB-to-Serial converter for Docklight Monitoring Mode (passive RS232 monitoring). The computer randomly reboots / shows a stop error / “Blue Screen of Death” / BSOD. How do I fix this?

Applies to: Docklight / Docklight Scripting (all versions), Article ID: dl_prb025

Symptoms like a stop error / “Blue Screen of Death” are always rooted in the serial port driver, not by the Docklight application code itself. Many of these driver issues have been fixed by the chipset manufacturers over the years, and we always recommend to look for updated drivers on their product support web sites. Another increasing source of problems are counterfeit chipsets which are hard to spot and are rather common in noname / consumer-grade products.

Extra question – so why does everything look fine with other applications like Hyperterminal or Teraterm, but with Docklight Monitoring my computer crashes?

The reason is that Docklight accesses the serial port driver with much higher frequency than other applications do, to achieve highest monitoring accuracy possible. Docklight additionally performs ‘data forwarding’ in Monitoring Mode – all data received on one COM port is immediately re-transmitted on the second COM port and vice versa. This fast full-duplex read/write on two COM ports must be correctly supported by the RS232 device drivers.

So you experience ongoing problems even with up-to-date Windows device drivers, we suggest:

1) Use different / industry grade USB-to-RS232 equipment known genuine chipsets, e.g. from FTDI.

2) If not possible and you just have to keep using the problematic device: Disable ‘Data Forwarding’ in Docklight Monitoring Mode as described on the Docklight manual (see link below). Using this modifications, we were able to run a successful 24h test using a device which previous exhibited random crashes.

Docklight Expert Options: No Data Forwarding

e-mail to Docklight Technical Support

Plugable Prolific Drivers / PL2303 driver download