.. _user-io:

Operation: External User I/O
============================

.. figure:: /_common-all/_images/connector-db15.eps
    :target: _images/connector-db15.eps
    :width: 500px
    :align: center

    |product_full| D-Sub 15-pin BDx Interface user I/O connector (female) pin numbering

.. csv-table:: Complete pin listing and definitions available on the BDx Module D-Sub 15-pin external user I/O connector. Pins not listed have no connection.
   :file: _tables/operation-userio-pins.csv
   :header-rows: 1
   :widths: 10 15 15 60

.. _bdx-digital-outputs:

Digital Outputs
---------------

The |product_full| has eight digital output signals on its rear 15-pint D-Sub external user I/O. The External User I/O pin layout is defined in :ref:`user-io`. 

The digital outputs are used to monitor the |product_type|'s internal states. A pin will output +5V when a state is active and 0V when a state is inactive. The maximum output current per pin is 20 mA. 

When the |product_full| is in a normal operating state, FAULT (Pin 2) will show 0V and INTERLOCK (Pin 3) will show 5V, both with respect to GROUND (Pin 1).

When the |product_full| is in a faulted state, FAULT (Pin 2) will show +5V and INTERLOCK (Pin 3) will show 0V. 

INTERLOCK (Pin 3) is often used to tie in to existing interlock systems and is provided with an ORing diode for protection. 


.. _userio-references:

Grounds
-------

A ground pin is provided on the |product_full| 15-pin external user I/O connector on Pin 1 to be used as the reference ground for digital outputs.