You need to program the buttons as lines. Automatic selection just means the phone picks an available line automatically AFAIK.

orion3311, thank you.
I am not sure how to do that procedure?

I did it many years ago, but forgot.

alwayslearning

This is from the Merlin Admin manual:

For Non-Square Systems
You may not want your system to be “square”. For instance, you may have a WATS line
that you want to appear only on a few voice terminals. Or you may want a line to serve
as a personal line for someone’s exclusive use. For cases like these, you will first
assign all the lines that will appear on all voice terminals in the system (fewer than the
total number of lines). Then, you will use a different procedure to assign the remaining
lines to particular voice terminals.
Here’s the procedure to assign the lines that will appear on all voice terminals in the
system:
Enter administration mode at the administrator/attendant voice terminal if you
haven’t already done so (see page 17).
Dial * 4 plus the number of lines in your system that you want to appear on all
voice terminals, making cetain these lines are the first ones to be plugged into
the control unit.
Now you can add the remaining unassigned lines to particular voice terminals using
the following procedure:

At the administrator/attendant voice terminal, select the voice terminal to be administered by touching the Intercom Auto Dial button (or dialing the intercom number)
of that particular voice terminal.
After you’ve dialed the number, green lights will be on next to line buttons
corresponding to assigned lines on the phone being administered. Line buttons
corresponding to unassigned lines will not have green lights next to them.
Touch the button corresponding to the line you want to add to the voice terminal.
When the green light comes on, the line has been added to the voice terminal.
Repeat this procedure for each phone.
If you do not want to administer other options, leave administration mode by
sliding the T/P switch back to the center position at the administrator/attendant
voice terminal and by setting the Admin/Normal switch back to Normal at the
control unit. Otherwise continue administration procedures.
You can also remove a line from a voice terminal by using the same procedure. The
green light will go off next to the line button.
When you remove a line from a telephone, the corresponding button becomes an
Outside Auto Dial button at that telephone.
Your MERLIN system is now ready for us

For Square Systems
You may have decided to configure lines in your system for “square” operation.
Square operation means that each voice terminal has all of the lines in the system
appearing on it, and each line is on a separate button.
Square is simple and easy for everyone in the system to understand. This form of
operation is familiar to many people who have worked with key telephone systems in
the past, for example, COM KEY® systems. The buttons and lights for all these lines
help you keep track of your calls.
If you want all lines to appear on all telephones, use the following procedure on the
administrator/attendant voice terminal:
Enter administration mode at the administrator/attendant voice terminal if you
haven’t already done so (page 17).
Dial * 4 plus the total number of lines in your system.
If you do not want to administer other options, leave administration mode by
sliding the T/P switch back to the center position at the administrator/attendant
voice terminal and by setting the Admin/Normal switch back to Normal at the
control unit. Otherwise, continue administration procedures.

I could only find my Merlin Plus manual.

Do you have a link to the exact manual you referenced?

While I was at the job, and just now, I am looking at manuals pages 4 -5 ,but do not see what you have mentioned? or at least a veiled hint?

Thank you

alwayslearning

Hi,

The manual name is:
ADMINISTRATION MANUAL:
MODELS 206,410, AND 820
WITH FEATURE PACKAGE 2

Pages 18.

https://www.bellsystemmemorial.com/pdf/bsp/9995041...

Hope this helps!

Thank you Jim E

alwayslearning

So today I went to the site to program Squared line selection.

However, there was no Admin switch anywhere on this particular Merlin KSU.

So I tried to do a *84 + 2 digit line code, but I was not sure of the line codes?

alwayslearning