Siemens AC75 Benutzerhandbuch

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AC75_ATC_V01.002

Page 508 of 569

10/30/06

Confidential / Released

This chapter describes the AT commands needed to access and configure the GPIO pins of the AC75. 

Please also refer to 

 for electrical specifications of the GPIOs and their signal states after startup and during

application. 

Except for the pulse counter commands, usage of all GPIO commands is restricted to the same interface where

the GPIO driver was openend with 

. Any attempt to access GPIOs from another interface will be denied

with an error message. 

When the AC75 starts up, all GPIO pins are set to high-impedance state after initializing. Therefore, it is recom-

mended to connect pull-up or pull-down resistors to all GPIO pins you want to use as output. This is necessary

to keep these pins from floating or driving any external devices before all settings are done by AT command (at

least 

), and after closing the GPIOs again. 

The 

 write command opens and closes the general purpose IO driver. The command must be executed

before any other GPIO command can be used. After closing the driver, all pins used (i.e. opened) will be put into

high impedance state (inputs) with no internal pull up or down.

The command does not reserve any general purpose IO pin, only the drivers required for GPIO pin management

will be loaded. 

0

Close General purpose IO driver

1

Open General purpose IO driver

Test Command

AT^SPIO=?

Response(s)

^SPIO:

(list of supported 

OK

Write Command

Response(s)

OK

ERROR

+CME ERROR: <err>

Reference(s)

PIN

ASC0 ASC1 USB MUX1 MUX2 MUX3 Charge

4

Last

SIEMENS

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