I Ntroduction To Display Station Operation; Introduction To Display Station Operation - IBM 3270 Operator's Manual

If possible, sit at a display station as you read this part of the
book so that you can use the switches and keys as you read
about them. By doing this, you can more quickly become a
skillful 3270 operator. If your display station has a keyboard
attached and if some point is not clear as you read, pause for a
moment to press the key and watch the result. Keep in mind,
however, that the purpose of some of the control keys is to
notify the computer that your display station requires service by
the program. Pressing any of these keys when the System is
ready (SYSTEM AVAI LAB LE indicator is on) interrupts the
program. In case you do not have a keyboard provided with your
display station, you'll only be required to make initial adjust-
ments to the display station (as explained in this section).
If your organization has what is called a sign-on procedure
and your display station is not signed-on, you can press any key
without affecting the program or the computer. A sign-on
procedure allows the program to ignore any interrupts received
from an unsigned-on display station.
There are many variations of the three basic types of 3270
display stations shown in Figure 1 on page 6. Operating
procedures are similar even though screen sizes and appearances
of some of the units are slightly different.
The only difference between the two upper displays is that
the larger screen holds four times as many characters as the small
one. Their indicators and controls are the same, and display
station operation is identical.
The labels located to the right of the screen are indicator
names. Display stations like the two top ones in Figure 1 have no
lights associated with these names. An area of the screen directly
beside each of the three labels displays a bright square as an
indication of the associated condition.
The combination power on/off and brightness/contrast con-
trol switch is located near the screen's lower-left corner (labeled
OFF-PUSH). The brightness/contrast control feature of the
switch allows you to adjust the display intensity to a comfor-
table viewing level.
3275 display stations like the bottom one handle their own
communications with the computer, usually over telephone lines.
They have eight indicators and use small lights to indicate the
conditions. Three of these indicators are identical, in name and
purpose, with the three on all the other display stations. The
other five indicators have been added to tell the operator of the
communications as they are taking place. When the indicators are
discussed, the three common ones will be presented first,
followed by the five that are used only on displays like the one
on the bottom.
Operating the 3270 .
5
INTRODUCTION TO DISPLAY
STATION OPERATION
I