Light Pen Connection - Keithley 708 Instruction Manual

Input-Displays the present status of the digital inpul on the
LED matrix. Logic high is indicated by a lit LED. The digital
input display status is continuously updated. Table 3-l lists
digital input display formats.
Kow/Column
Al
BI
Cl
DI
El
Fl
Gl
HI
Input #
I
2
3
4
5
6
7
8
Row/Column
A2
82
c2
D2
E2
F2
G2
H2
Input #
9
I 0
II
I2
I3
14
I5
I6
Output-Displays the present status of the digital output on
the LED matrix. The output can bc changed by clicking the
light pen on the appropriate LED. Output high is indicated
by a lit LED. Output low is indicated by an extinguished
LED. The digital output display status is updated when the
output is changed. Table 3-2 lists digital output display for-
mats.
Table 3-2
Digital olrtput displayfirmats
I
1
iow/Column
A12
1312
Cl2
Dl2
El2
F12
Gl2
HI2
3utput #
9
IO
II
I2
13
I4
I5
I6
3.2.2 light pen connection
LIGHT PEN -An optional input device for toggling Ihe
on/off state of the crosspoint display LEDs and digital I/O
LEDs. One Ii&t pen is uxd to control the I.EDs of up to live
Model 708 mainframes. Rcfcr to Figure 3 I for the location
ofthc light pen connection. Refer to pxagraph 4.4.4 for light
pen operating information.
3.2.3 LED indicators
IEEE-488 STATUS INDICATORS
TAI.K, LSTN, REM - Thcsc three I.ED indicators apply
to instrument operation over the IEEE-JXX bus. The TALK
and LSTN indicators show when the unit has been addrcsscd
to talk or listen. REM turns on to show when the unit is in the
IEEE-488 rcmotc state. Set Section 4 for detailed inform;\+
don about operation over the bus.
OTHER STATUS INDICATORS
ERR ~ This LED lights when an CITOT conditiun is Ilagged.
The error condition is flagged in the serial poll byte when any
bits in the Error Status Word xc set. Refer to paragraph
5.9.20 for inlonnation on sending the Eror Status Word
(command Ul).
COPY- When this LED is lit, any change to the crosspoint
display is immediately sent LO the rcleys. Rcfcr to paragraph
3.2.4 for information on toggling the COPY LED.
3.2.4 Switches/connections
POWER -The power switch turns the unit on or off. The
unit is on when the POWER pushbutton is in (depressed) and
off when the POWER pushbutton is out.
CAUTION
The position ofthe POWER pushbutton
indicates the power status of the Model
708 Switching System. The status of the
crosspoint display and the other LEDs
are not indications of power being ap-
plied to the Model 708.
R-3