This 1-byte field defines certain general session characteristics. These characteristics are:

Bit setting 0123 4567

(Byte 23) Meaning

..0. ....

The primary logical unit can send data first.

..1. ....

The secondary logical unit must send data first.

.... 0...

The secondary logical unit initiates attended.

.... 1...

The secondary logical unit initiates unattended.

.... .0..

The secondary logical unit does not alternate between attended and unattended.

.... .1..

The secondary logical unit alternates between attended and unattended.

xx.x ..xx

Reserved.