content_image/976642.jpg content_image/976649.jpg content_image/976643.jpg content_image/976648.jpg
<img src='content_image/976642.jpg'>

Each port has two LEDs that display the status of its activity. Their meanings are shown in Table 12-5. 

<img src='content_image/976649.jpg'>

## Canister status 

The status of each expansion canister is displayed by three LEDs on the back of the unit, as shown in Figure 12-18. 

<img src='content_image/976643.jpg'>

The meaning of each LED is listed in Table 12-6. 

<img src='content_image/976648.jpg'>

