Siemens AC75 manual Example Using I²C Bus

AC75 AT Command Set

19.8 AT^SSPI

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19.8.5Example: Using I²C Bus

As stated above, it is recommended to run the Terminal program in chat mode or to use the local echo. First, activate the I²C interface:

AT^SSPI=0010,0000,0000,0000,0000

CONNECT

The first group of characters forms the <basicCon- figuration>, where the first "0" sets I²C, the sec- ond "0" is the internal port, the digit "1" sets 400 kbps bit rate on the I²C bus, and the next "0" selects ASCII coding. This is followed by a comma and the value "0000" = no delay time after Write and Read.

Note: If omitted all above parameters are assumed

by default. Therefore, instead of AT^SSPI=0010,0000,0000 it is sufficient to enter only AT^SSPI=

The module is in data mode now. This allows you to send a Write Transfer Message:

<aAE000102030405060708090A0B0C0D0E0F>	Write Transfer Frame, where a = ID, AE = Slave
	Address and write request.
{a+}	Write Response Message, where a = ID.
<bAF0010>	Read Transfer Message, where b = ID, AF = Slave
	Address and read request, 0010 = number of
	expected bytes.
{b+000102030405060708090A0B0C0D0E0F}	Read Response Message, where b = ID.

To quit data mode and return to command mode enter the Close character "#":

#	The response OK confirms that the ME is back to
OK
	command mode and ready to accept any AT com-
	mands.

If the ME is in command mode, the response to the read command contains the factory settings.

AT^SSPI?	The read command returns the connection state "not
AT^SSPI=0,0010,0000,0000
	connected" (Channel closed) and the factory set-
	tings for I²C.
OK

If the ME is in data mode, the response to the read command contains the current settings.

AT^SSPI?	The read command returns the connection state
AT^SSPI=1,0010,0012,00FF,0000,0000
	"connected" (Channel open) and the current settings
	for I²C.
OK

AC75_ATC_V01.002	Page 504 of 569	10/30/06
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