CEP AG
Revision 1.2
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Page 8 of 28
2.1.2 Digital Output - GT864 PY Variant only
switched voltage is V
IN
; high side switch
max. Output 400mA
short circuit protected
ESD protected
under full control of embedded application
The following command has to be used to initialise and to set the digital output:
AT#GPIO=3,1,1 output
switched
on
AT#GPIO=3,0,1 output
switched
off
2.2 Mini USB Connector
There exist several different variants of the terminal module, all in (almost) the same
housing, and all equipped with the USB-type connector:
GT864 QUAD with Audio
The GT864-QUAD Terminal provides "audio signals" on that connector, so
you can connect a handset or microphone/speaker system here (available for
the GT864 QUAD only)
GT864 PY with GPIO
The programmable GT864-PY provides digital inputs on that connector, so
you can use external digital signals to control the behaviour of the terminal
thereby (available for the GT864 PY only)
You will find the version of your GT864 terminal (PY or QUAD) at the label on the
button of the device.
By their nature all these 2 different signals are completely different regarding voltage
levels, signal direction and applied energy. Especially the audio signals are quite
sensitive to over-voltage, but they are protected against it to a limited extend only,
since otherwise the audio signal would be significantly deteriorated.
So please make sure you are using the right variant for your application and do not
mix up different variants -
especially do not drive any digital signals into the
USB-type-connector of the audio-variant, since that might seriously damage
the device.
