Keithley 7022, Instruction Manual

Page: 56 / 107

Operation
5-2
Channel assignments
The Model 7001 has a channel status display (Figure 5-1)
that provides the real-time state of each available channel.
The left portion of the display is for slot 1 (card 1), and the
right portion is for slot 2 (card 2). For the Model 7002, chan-
nel status LED grids are used for the ten slots. The LED grid
for slot 1 is shown in Figure 5-2.
Figure 5-2
Model 7002 channel status display (slot 1)
Organization of the channel status display for each slot is
shown in Figure 5-3. The card contains 40 channels and
is made up of a 5
×
6 matrix using 30 channels, with each
channel designated as a row/column crosspoint, and ten dig-
ital output channels.
The matrix rows can be jumpered to the backplane of the
mainframe to expand matrix inputs.
All digital input and output channels are isolated from the
backplane of the mainframe. With the mainframe in the nor-
mal display state, the status (on or off) of the output and
matrix crosspoint channels is displayed. When the main-
frame is in the read input channels mode, the status (on or
off) of the input channels is displayed.
The hardware for the digital output channels is user config-
urable for negative or positive true logic. That is, depending
on the user configuration, the output can go high or be pulled
low when the channel is turned on (closed) or off (open). To
configure output logic, refer to Section 4.
Input channels use positive true logic but can be configured
to pull up or pull down. Thus, a channel can be pulled high
or pulled low when the input is open depending on the
jumper configuration. Input channels will be displayed as
high (on) when the input has a high logic level applied. Con-
versely, an input channel will be displayed as low (off) when
a low logic level is applied.
To control the card from the mainframe, each matrix cross-
point and digital output must have a unique channel assign-
ment. The channel assignments for the card are provided in
Figure 5-4. Each channel assignment is made up of the slot
designator (1 or 2) and the matrix crosspoint or digital output
channel. For the Model 7002, the slot designator can be from
1 to 10 since there are ten slots. To be consistent with Model
7001/7002 operation, the slot designator and channel are
separated by exclamation points (!). Some examples of chan-
nel assignments:
CHANNEL 1!1 = Slot 1, Channel 1 (Row A, Column 1)
CHANNEL 1!40 = Slot 1, Channel 40 (Output 40 of
Digital I/O)
CHANNEL 2!2 = Slot 2, Channel 2 (Row B, Column 1)
CHANNEL 2!34 = Slot 2, Channel 34 (Output 34 of
Digital I/O)
These channels are displayed and controlled from the normal
display state of the mainframe. If currently in the menu
structure, return to the normal display state by pressing
EXIT.
CARD 1 CARD 2
1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10
= Open Channel
= Closed Channel
7001 Display
Figure 5-1
Model 7001 channel status display
1
2
3
4
1 2 3 4 6 7 8 5 9 10
SLOT 1
ROW
COLUMN
= OPEN CHANNEL
= CLOSED CHANNEL
7002 LED DISPLAY
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