.. _headlabel-refx-data-87:

Data 87 (External Power Voltage)
================================

The basic information of the external power supply.

The frame format of the Data **87** unit is as follows:

.. code-block:: none

   For example (Total 5 bytes):
   57 03 01 2E E0

.. tabularcolumns:: |p{3.2em}|p{12.2em}|p{5.8em}|p{13em}|p{4.8em}|

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

   +---------+--------------------------------------------+---------------+---------------------------------------------+--------------+
   | Parts   | Fields                                     | Length (Byte) | Range/Format                                | Default      |
   +=========+============================================+===============+=============================================+==============+
   | ID      | Data ID                                    | 1             | 57H (87)                                    | 57H (87)     |
   +---------+--------------------------------------------+---------------+---------------------------------------------+--------------+
   | Length  | Data Length                                | 1             | 00H or 03H                                  |              |
   +---------+--------------------------------------------+---------------+---------------------------------------------+--------------+
   | Content | `Connection Status`                        | 1             | 00H-01H                                     |              |
   +         +--------------------------------------------+---------------+---------------------------------------------+--------------+
   |         | `Voltage`                                  | 2             | 0000H-FFFFH (mV)                            |              |
   +---------+--------------------------------------------+---------------+---------------------------------------------+--------------+

- `Connection Status`

  Whether the external power supply is connected.

  - **00H** - Not connected.

  - **01H** - Connected.

- `Voltage`

  The external power supply voltage of the terminal device. Expressed as a 16-bit unsigned integer and the unit is mV.
  The field indicates the exact current voltage vlaue only when 'Connection Status' is 01H (Connected). If the 'Connection Status' is 00H (Not connected), then the value of this field is normally 0000H, FFFFH, or the last voltage value read.