Allied Telesyn AT-A14AT-A15/SX Guía De Instalación Rápida página 16

If you are installing only one expansion module in the switch, it is
recommended that you install the module in slot A. While the module
will work in slot B with slot A empty, the port numbering assignments
will change if you later install a module in slot A. This could affect the
VLAN memberships on the switch and this could require you to adjust
your VLAN configurations.
For example, if you install an AT-A14 in slot B of an AT-8224XL
switch while leaving slot A empty, the switch will assign the port
number 25 to the port on the new module. If you later install another
AT-A14 in slot A, the switch will automatically reallocate port number
25 to the new module in slot A and assign the port number 26 to the
module in slot B. If the module in slot B had been a member of a VLAN
other than the Default VLAN, you would be required to reconfigure
the VLAN to reflect the change to the module's port number.
3. Remove the expansion module from the packing material.
Caution
To prevent damaging the module, be sure to observe ESD precautions.
4. Slide the module into the empty slot making sure the board is aligned
properly with the card guides. Refer to Figure 2.
Card Guide
Dust Cover
6
A T -A 1 5
A C TI VI TY
LI N K
FU LL D U
1 0 0 0 B A S
P
E -X
H A LF D U
C O L
P
Figure 2 Installing an Expansion Module
A
B
Board