MO - Primary Monitor Period
---------------------------

This transaction is used to specify the primary monitor at a site for NAAQS purposes. A primary monitor period may be created for any parameter, but are required for the following:

*  14129 (TSP Lead at LC)
*  85129 (PM10 Lead at LC)
*  42602 (NO2)
*  88101 (PM2.5)

When monitors for these parameters are created at a site, a primary monitor period record for that parameter must be in effect for the site. AQS uses this record to perform site level data combinations and data substitution of missing values for NAAQS-related calculations.

If only one monitor for a listed parameter exists at a site, then that monitor will be the primary monitor for the site. Primary monitor periods are specified for date ranges.

Examples:

.. code-block:: text
   :caption: MO transaction in default mode

   MO|I|TT|614|7001|88101|1|20020701|20030821|

.. code-block:: text
   :caption: MO transaction in Tribal mode

   MO|I|TT|183|0001|88101|1|19990501|19990502|



Format
^^^^^^

.. list-table:: MO - Primary Monitor Period transaction format
   :widths: 1 5 15 4 3 1
   :header-rows: 1


   * - Seq.
     - Name
     - Description
     - Formatting Rules
     - Required
     - Key
   * - 1
     - `Transaction Type <Transaction%20Type.html>`_
     - Monitor Primary Period transaction identifier.
     - Must = MO
     - Always
     - 
   * - 2
     - `Action Indicator <Action%20Indicator%20for%20Transaction.html>`_
     - Indicator for Insert, Update, or Delete action.
     - Must = I, U, or D
     - Always
     - 
   * - 3
     - `State Code / Tribal Indicator <State%20Code.html>`_
     - The FIPS state code of the monitor, or "TT" to indicate that the next field on the transaction is a Tribal code.
     - Must exist in STATES Reference Table or be 'TT' for Tribal Site
     - Always
     - Y
   * - 4
     - `County Code / Tribal Code <County%20Code.html>`_
     - The FIPS County Code of the site.  If the previous field on the transaction contains "TT", then the Tribal Code of the site.
     - Must exist in COUNTIES (for state) or TRIBAL_AREAS Reference table
     - Always
     - Y
   * - 5
     - `Site Number <Site%20Number.html>`_
     - Four digit number to uniquely identify site in county and/or tribe.
     - Must exist in SITES table with {State Code, county Code} or Tribal Code
     - Always
     - Y
   * - 6
     - `Parameter Code <Parameter%20Code.html>`_
     - The AQS parameter code assigned to the monitor in AQS.
     - Must exist in PARAMETERS reference table.
     - Always
     - Y
   * - 7
     - `POC <POC.html>`_
     - Parameter Occurrence Code:  One or two digit number identifying a specific monitor for a parameter at the site.  
     - Must exist in MONITOR table for non-Insert actions.
     - Always
     - Y
   * - 8
     - `Begin Date <Begin%20Date.html>`_
     - Beginning of date range where the monitor is the primary for the parameter at the site.
     - YYYYMMDD.
     - Always
     - Y
   * - 9
     - `End Date <End%20Date.html>`_
     - End of date range where the monitor the primary for the parameter at the site.
     - YYYYMMDD.
     - No
     -