Note: this procedure is for USB to Serial cables that use the FTDI chip set.
Once the included driver is installed (takes about 30 seconds) the
latency setting needs to be changed. The following guide shows how this
is done. This guide was created on an XP box.
Be sure to leave the USB to Serial adapter cable plugged into the USB port while making this change.
First is to open the Device Manager. Here are two methods of doing this. Both are from a right click of the mouse.
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The left picture is from the "My Computer" desktop ICON. The right picture is from Windows Explorer.
Be
sure to right click the mouse to get the small drop down menu. Then
click on Manage for the "Computer Management" dialog:
On
the left pane click on "Device Manager", then move to the right pane
and expand the "Ports (COM & LPT)" entry (click on the + in the
box).
Right click on the "USB Serial Port (COMx)" entry, a drop down will appear:
Click on the "Properties" entry. The FTDI driver Properties dialog menu will appear.
Click on the "Port Settings" tab at the top, then click the "Advanced" button.
The final dialog will appear:
The "Latency Timer (msec)" setting is to be changed. Click on it then select or enter 10.
Click on the OK button, and follow back through the dialogs clicking OK in turn.
Notes:
If
flashing a new calibration fails during the verify, lower the latency
setting further. Try 8, then 6, then 4 until it works every time.
On
Windows 7, some installations will reset the latency back to 16 when
re-booted. So check the latency and reset it until it 'sticks.'
If
the latency setting is left high the What's Up Display will be able to
data log and do VE Learns and such. Where there will be issues is with
flashing a new calibration. There will be intermittent failures in the
process. Sometimes it will work, other times it won't. The flashing may
work OK but then the verify fails.
Lowering the latency
timer corrects these issues. With the proper setting there should never
be a failure to flash, verify, or set the bank active.
Copyright 2006-2023 Dynamic
EFI, All Rights Reserved. No part
of this document may
reproduced in any form or posted on a web site without
expressed documented permission from Dynamic EFI
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