IBM 3270 Manual page 242

( ;
~/
Loop Data Speed Switches (Loop Adapter Feature Only)
The Loop Data Speed switches are installed only on 3274 Model 51C
Control Units that have the Loop Adapter feature (#4850) to attach to a
4331 Processor or to an 8100 Information System loop. These switches are
used to select the primary and secondary loop data speeds. If the loop
operates at a carrier speed of 9600 bps, the operator can switch the loop
data speed by using the Pri/Sec switch on the Model 51C operator panel.
[I~
the loop operates at a carrier speed of 38,400 bps, the Sec (Secondary)
position of the Pri/Sec switch should not be used.] ·
To determine the Loop Data Speed settings, first select the table in. Figure
H-2 for the loop carrier speed, either 9600 bps or 38,400 bps. Using this
table, find the primary and secondary loop data speeds that your systeiµ is
going to use. The switch settings are shown· to the left of the loop data
speeds you select. Fill in the switch settings on the instructions following
Figure H-2. Give the completed instructions to the person who will
customize your Model 51 C.
For a loop carrier speed of 9600 qps, use
the following table:
Loop Data Speed Line Speed
Switch Setting (bps)
2 3
Pri Sec
Off Off Off
"9600 4800
Off Off On
9600 2400
Off
On
Off
4800
2400
On
Off
Off
2400
1200
For a loop carrier speed of 38,400 bps
(direct-attached loop only), use the
following table:
Loop Data Speed
Switch Setting
2 3
Off Off Off
On Off Off
*Do not use.
Line Speed
(bps)
Pri Sec
38,400
9600
Figure H-2. Loop Data Speed Switch Settings. (See sequence number 347
for additional information
on
changing loop speed selection.)
Appendix H. Planning for 3274 Model 51C Switch Settings
H-5