LSI SYM22801 - Manual (Page 28)

2-14 Installing the SYM22801 Host Adapter
Figure 2.9 Using Both Internal Connectors on a Channel
Note: When two connectors are already used on a channel, the
third connector cannot be used.
Step 6. Most PC cabinets are designed with a front panel LED
(sometimes already connected to an existing IDE drive). You
may connect this LED cable to the host adapter, as shown in
Figure 2.10. This causes the front panel LED to indicate activity
on the SCSI bus.
This connector is not keyed. The orientation of the LED cable
does not matter as long as all four pins are connected.