Siemens 7 - Manual (Page 17)

Multiplexer Driver Developer’s Guide
2.8 Power Down
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Mux_Drv_DevGuide_v07 Page 17 of 36 2006-9-27
Confidential / Released
2.8.3 Power Down on PC Shutdown
When the PC is shut down, the multiplexer mode is turned off and the strings from the Registry value “ShutDown”
are sent to the module, if a virtual port is in use.
Note: During shutdown, some PCs may generate an impulse on the lines of the serial interface. In applications
where the DTR line connects to the ignition line (IGT), an impulse received on DTR will immediately cause the
module to be restarted from Power Down mode.