3Com WX1200 Reference Manual page 199

If a USM user with access type read-write-notify, read-notify, or
notify-only is already configured, you can select it. Otherwise, you must
create a new one. You also can create a new USM user even if one is
already configured.
To create a new USM user:
a If a list of USM users is displayed, select Create new USM User and
click Next.
b In the Username box, type the name of the SNMPv3 user. The name
can be 1 to 32 alphanumeric characters, with no spaces or tabs.
c Select the access type.
read-notify—An SNMP management application using the string
can get object values on the switch but cannot set them. The
switch can use the string to send notifications.
notify-only—The switch can use the string to send notifications.
notify-read-write—An SNMP management application using the
string can get and set object values on the switch. The switch can
use the string to send notifications.
d Select the Engine ID format:
Hex—ID is a hexadecimal string.
IP—ID is based on the IP address of the station running the
management application. Enter the IP address of the station. MSS
calculates the engine ID based on the address.
LocalID—Uses the value computed from the switch's system IP
address.
To send informs, you must specify the engine ID of the inform
receiver. To send traps and to allow get and set operations and so on,
specify local as the engine ID.
If you select Hex or IP, type the hexadecimal string or IP address in the
Value box.
To configure authentication and encryption settings, finish this
procedure, then select the USM user and click Properties.
8 Click Finish.
Viewing and Changing Management Settings 199