Troubleshooting
DLoG ITC 7
User’s Manual
75
15.
Troubleshooting
15.1.
COM1 / COM2 data transmission
To avoid transmission problems in serial transmission, DLoG GmbH
always recommends transmission with hardware handshake.
If problems arise when transmitting data via a serial interface COM1 or COM2 (e.g. data
is lost or is not detected), please follow the steps described here.
Please note the different procedures for MS-Windows and MS-DOS operating systems!
Step 1: Change power saver BIOS settings
1.
In BIOS setup, open the menu
Advanced | CPU Configuration
.
2.
Go to the setting
C2 State Support
.
Here,
Enabled
is set by default.
3.
Change this setting to
Disabled
.
The setup line
C3 State Support
is automatically also set to
Disabled
.
4.
Save that BIOS setting and leave the BIOS setup.
This BIOS setting applies to all COM ports.
Technical background: The changed setting affects the computer's power saving
mechanism. If the power saving mechanism
C2 State Support
is set to
Disabled
, no
SMIs will be generated when switching processor states between C1=>C2=>C2 and
back to C1, which may lead to "lost" bytes on the RS232 interface. The setting
C2 State
Support
is also called
Stop-Clock State
; the
C3 State Support
is the so-called
Sleep
State
.
