Turn On/Off Ac75 Applications With Integrated Usb - Siemens AC75 Hardware Interface Description

AC75 Hardware Interface Description
Strictly confidential / Preliminary
3.3.3.3

Turn on/off AC75 Applications with Integrated USB

In a Windows environment, the USB COM port emulation causes the USB port of AC75 to
appear as a virtual COM port (VCOM port). The VCOM port emulation is only present when
Windows can communicate with the module, and is lost when the module shuts down.
Therefore, the host application or Terminal program must be disconnected from the USB
VCOM port each time the module is restarted.
Restart after shutdown with AT^SMSO:
After entering the power-down command AT^SMSO on one of the interfaces (ASC0, ASC1,
USB) the host application or Terminal program used on the USB VCOM port must be closed
before the module is restarted by activating the IGT line.
Software reset with AT+CFUN=x,1:
Likewise, when using the reset command AT+CFUN=x,1 on one of the interfaces (ASC0,
ASC1, USB) ensure that the host application or Terminal program on the USB VCOM port be
closed down before the module restarts.
Note that if AT+CFUN=x,1 is entered on the USB interface the application or Terminal
program on the USB VCOM port must be closed immediately after the response OK is
returned.
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27.04.2006