# Installing an IOA Shelf

Use an IOA shelf (also called an IOA bracket) when installing half-height IOAs in the router. IOA shelves screw into the midplane between the upper/right bay (Adapter 0) and lower/left bay (Adapter 1). For example, in an E320 router, IOAs in the upper bay rest on the shelf, while IOAs in the lower bay use the guides on the bottom of the shelf to remain vertical. See Figure 20.

Figure 20: IOA Shelf

| Caution: We recommend that you power down the router before removing or installing an IOA shelf between two slots that have modules installed in them already. Otherwise, you might short-circuit the installed modules if you accidentally touch the shelf to a module. An IOA shelf installation guide is available to ensure safe installation. Contact your account representative for more information.

To install an IOA shelf:

1. Ground yourself by using an antistatic wrist strap or other device and connect it to one of the ESD grounding jacks.
2. Remove the blank IOA filler panel from the slot.
3. Align the shelf's guide pins with the corresponding holes in the midplane and insert the threaded shaft into the hole in the midplane between the upper/right bay and lower/left bay. Be sure the threaded shaft is visible from the right side. (See Figure 20.)
4. Using a flathead screwdriver, tighten the screw snugly to secure the shelf.