Rangecast FAQ
[FAQ-1084] Power cycle the USB system


Page Type: SOLUTION


OVERVIEW

On occasion, some element of the USB system (in either the PC or external hardware) may freeze (probably in firmware), and become unresponsive until it is power cycled. Simply turning a PC off/on may not clear the issue, since many PCs keep minimal power applied to some circuits. To ensure a clean power cycle of the USB hardware, physically disconnect the PC power cable for at least 30 seconds (with Windows safely shut down.)


METHOD

1) (optional) Attempt to clear any firmware lockup in the USB hardware of the PC/scanner interface box.

a) Locate the USB cables connecting the PC to the scanner interface box

b) Unplug these cables from the PC, and leave them unplugged for at least 10 seconds

c) Reconnect these cables, one at a time (note: after connecting one USB cable, wait at least five seconds before connecting the next one)

d) See if the problem has been resolved

Note: Step 1 is not required, as the full power cycle of step 2 will also clear such a firmware lockup. This step is provided as an optional quick-step that may resolve certain USB problems, since Step 1 is easier to perform than Step 2 (as it doesn't involve touching the PC power cable). But it is fine to skip Step 1, and proceed directly to Step 2.


2) Power cycle the PC (including a hardware disconnect from any source of power)

a) Shut down Windows

b) Wait for Windows to completely finish the shutdown process, and turn off

c) Physically disconnect power to the PC. This is usually best done by pulling the power cable from the back of the PC, but it can also be done at the other end of the cable.

Note: if the PC is powered through a UPS (uninterruptable power supply) to ensure operation through power failures, the PC must be disconnected from the UPS -- it will not be effective to disconnect the UPS from wall power.

d) Wait for 30 seconds

e) Reconnect power to the PC

f) Many PCs used for Rangecast are configured to automatically start when power is applied, and then automatically launch Rangecast software, to ensure operation resumes after power failures. If this does not happen, then take manual steps to restart the computer and/or relaunch Rangecast, as appropriate.


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