How to access multiple POS from one machine

Update the POS.EXE configuration file (original text further down on the page).
In addition to the original description, I want to provide the example file and what you will see at the POS when you start it.

Example File POS.EXE.CONFIG
<?xml version="1.0" encoding="utf-8"?>
<configuration>
    <configSections>
        <section name="AXRETAILPOSW7" type="LSRetailPosis.Settings.ConfigFile.AppConfiguration, SystemSettings, Version=5.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
        <section name="GTSCLAB" type="LSRetailPosis.Settings.ConfigFile.AppConfiguration, SystemSettings, Version=5.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
   </configSections>
    <AXRETAILPOSW7 LocalConnectionString="Data Source=LOCALHOST;Initial Catalog=AxRetailPOS;Integrated Security=SSPI;Persist Security Info=false;Pooling=false;TrustServerCertificate=true;Encrypt=TRUE"
        StoreId="S0002" TerminalId="0003" DatabasePhysicalFilePath="C:\Program Files\Microsoft SQL Server\MSSQL10_50.MSSQLSERVER\MSSQL\Data\"
        DATAAREAID="CEU" UseSnapshotIsolation="true"/>
    <GTSCLAB LocalConnectionString="Data Source=GTSCLAB-dk;Initial Catalog=AxRetailPOS;Integrated Security=SSPI;Persist Security Info=false;Pooling=false;TrustServerCertificate=true;Encrypt=TRUE"
        StoreId="S0001" TerminalId="0001" DatabasePhysicalFilePath="C:\Program Files\Microsoft SQL Server\MSSQL10_50.MSSQLSERVER\MSSQL\Data\"
        DATAAREAID="CEU" UseSnapshotIsolation="true"/>
</configuration>

Result:
It is now possible to connect to a different configuration / POS database


POS Technical Reference.pdf

Controlling startup

Starting
Microsoft Dynamics AX for Retail POS can be controlled by the config file and
startup parameters.

The config file

The
config file is an XML file whose file name is POS.exe.config. It is located in
the same directory as the EXE file. The config file is constructed as follows:

<?xml version="1.0"
encoding="utf-8"?>

<configuration>

<configSections>

<section name="FirstSection"
>

<section
name="SecondSection" >

</configSections>

<FirstSection
LocalConnectionString=" " LocalUserName=" "
LocalPassword="" .. other variables>

<SecondSection
LocalConnectionString=" " LocalUserName=" "
LocalPassword="" .. other variables>

</configuration>

As
shown above, the config file can have one or more sections specified within the
configSection tag. Each section must have its own tag and can have the
following parameters:

LocalConnectionString

Tells
Retail POS about the connection string. A typical connection string is shown in
the example config file above.

LocalUserName

Stores
an encrypted user name that connects to the database if integrated security is
set to false in the connection string. An unencrypted name can also be put
directly into LocalConnectionString.

LocalPassword

Stores
an encrypted password for the person who connects to the database; if
integrated, security is set to false in the connection string. An unencrypted
password can also be put directly into LocalConnectionString.

RemoteConnectionString,
RemoteUserName, and RemotePassword

Not
used by Retail POS. Retail POS Technical Reference Controlling startup 2

StoreId

The ID of the store. Because a number of settings are
store-related, changing the store ID can result in an error if related store
data is missing.

TerminalId

The ID of the POS register. When Retail POS starts, the
terminalID of the config file must match an entry found in the
RBOTerminalTable. Otherwise, an error occurs.

DataAreaId

This parameter equals the field DATAAREAID found in most of
the tables in the database. This field makes it possible to start Retail POS
with different data, depending on the dataareaid.

DatabasePhysicalFilePath

When Retail POS starts and no database is found, a database
is created. If you must create the database using a path other than the default
path, you can specify it in the parameter DatabasePhysicalFilePath.

UseLocalSqlExpress

If this is set to true, Retail POS does not install
Microsoft SQL Server Express.