Primary Line Speed/Secondary Line Speed Switch; Snbu/Non-Switched Line Switch; Sdlc/Bsc Switch; Communicate/Local Switch (Loop Adapter Feature Machines Only) - IBM 3270 Manual

Primary Line Speed/Secondary Line Speed Switch
This switch is installed on all 3276s, except those with the DDSA feature and is normally
set to the Primary (up) position. When the switch is in the Primary (up) position, the
primary communication line speed is selected; when the switch is in the Secondary (down)
position, the secondary (half-speed backup) speed is selected. Fill in item 4 of the 3276
Switch Setting Form.
SNBU/Non-Switched Line Switch
SDLC/BSC Switch
This switch is installed if the 3276 (1) has an integrated modem with Switched Network
Backup (SNBU) feature and is attached to a nonswitched line or (2) has an external
modem and is connected to a nonswitched line. The switch is normally set in the Non-
Switched line (down) position. To select the switched network backup, place the switch
in the SNBU (up) position. Fill in item 5 of the 3276 Switch Settings Form.
This switch is installed if the 3276 has the SDLC/BSC Switch feature. The function of
the switch is to select either SDLC or BSC line control. Fill in item 6 of the 3276 Switch
Settings Form.
Note: This switch is interrelated with switch B6, the FDX/HDX switch. See Figure D-3.
Communicate/Local Switch (Loop Adapter Feature Machines Only)
This switch is installed if the 3276 has the loop Adapter feature. Set the switch to the
Communicate (up) position to perform the communicate operation as a unit attached to
the loop. Fill in item 7 of the 3276 Switch Settings Form.
Note: When the switch is in the Local {down) position, the 3276 is electrically discon-
nected from the loop. Changing the setting of the 1/0 switch {Power On/Off switch) or
performing the 3276 local operation, such as the Subsystem test, does not interfere with
the communicate operation of the other units that are attached to the loop.
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