.. _headlabel-refx-cmd-eps:

EPS (External Power Supply)
===========================

The `AT@EPS` command is used to configure the alarm threshold of the external power supply of the terminal.

When the external power is connected and the external power voltage is below the limit value (specified by 'Low Voltage Threshold'), the terminal will be in the state of low external voltage.
In this state, the terminal will enter Profile 11 (Low Power) and trigger an external low voltage alarm (refer to :ref:`Record 23H <headlabel-refx-record-23>`).

.. code-block:: none

   Example:
   AT@EPS=gv500cna,,12000,60,,,012F$
   +ACK:EPS,123456789012345,8203,3,0,,012F,20210407101530,1234$
   AT@EPS?gv500cna,,0C37$
   +QRY:EPS,123456789012345,8203,3,0,1,1,,12000,60,,,0C37,20210407101530,1234$

.. tabularcolumns:: |p{2.2em}|p{15em}|p{5.8em}|p{12em}|p{4em}|

.. table::
   :width: 100%
   :widths: auto

   +-------+---------------------------------+---------------+---------------------------------------+--------------------+
   | Parts |              Fields             | Length (Byte) |                  Range/Format         |    Default         |
   +=======+=================================+===============+=======================================+====================+
   | Head  | Header                          | 3             | AT@                                   | AT@                |
   +       +---------------------------------+---------------+---------------------------------------+--------------------+
   |       | Command Word                    | 3             | EPS                                   | EPS                |
   +       +---------------------------------+---------------+---------------------------------------+--------------------+
   |       | Leading Symbol                  | 1             | =                                     | =                  |
   +       +---------------------------------+---------------+---------------------------------------+--------------------+
   |       | Password                        | 8-16          |                                       | gv500cna           |
   +-------+---------------------------------+---------------+---------------------------------------+--------------------+
   | Body  | Reserved                        | 0             |                                       |                    |
   +       +---------------------------------+---------------+---------------------------------------+--------------------+
   |       | `Low Voltage Threshold`         | <=5           | 0 or 8000 - 28000 (mV)                | 0                  |
   +       +---------------------------------+---------------+---------------------------------------+--------------------+
   |       | `Low Voltage Debounce Time`     | <=4           | 5-3600 (seconds)                      | 5                  |
   +       +---------------------------------+---------------+---------------------------------------+--------------------+
   |       | Reserved                        | 0             |                                       |                    |
   +       +---------------------------------+---------------+---------------------------------------+--------------------+
   |       | Reserved                        | 0             |                                       |                    |
   +-------+---------------------------------+---------------+---------------------------------------+--------------------+
   | Tail  | Sequence Number                 | 4             | 0000-FFFF ('0'-'9', 'A'-'F')          |                    |
   +       +---------------------------------+---------------+---------------------------------------+--------------------+
   |       | Tail                            | 1             | $                                     | $                  |
   +-------+---------------------------------+---------------+---------------------------------------+--------------------+

- `Low Voltage Threshold`

  Specify the low power threshold. When the voltage of external power is below this value longer than 'Low Voltage Debounce Time', the terminal will be in the state of low external voltage. If it is set to 0, this function is disabled.

- `Low Voltage Debounce Time`

  The debounce time for checking the 'Low Voltage Threshold'.