Operation
3-2
the right portion is for slot 2 (Card 2). For the Model 7002,
channel status LED grids are used for the 10 slots. The LED
grid for slot 1 is shown in Figure 3-2.
Input/output channel organization of the channel status
display for each slot is shown in Figure 3-3. The card
contains 40 independent input channels and 40 independent
output channels. All input and output channels are isolated
from the backplane of the mainframe. With the mainframe in
the normal display state, the status (on or off) of the output
channels is displayed. When the mainframe is in the read
input channels mode, the status (on or off) of the input
channels is displayed.
Output channels use negative true logic. That is, the output is
pulled low when the channel is turned on (closed).
Conversely, the output goes high when the channel is turned
off (open).
Input channels use positive true logic. A channel is on
(closed) when the input is high. Keep in mind that an open
input is pulled high by the internal pull-up resistor. Con-
versely, a channel is off (open) when the input is pulled low
to ground.
1
2
3
4
5
6
7
8
9
10
1
2
3
4
5
6
7
8
9
10
7001 DISPLAY
= OPEN CHANNEL
= CLOSED CHANNEL
CARD 1
CARD 2
Figure 3-1
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
Figure 3-2
Model 7002 channel status display (slot 1)
3.4
Channel assignments
Each input and output channel has a CHANNEL assignment,
which includes the slot number that the card is installed in.
Figure 3-4 shows the CHANNEL assignments for slots 1 and
2. Each CHANNEL assignment is made up of the slot desig-
nator (1 or 2) and the channel (1 to 40). For the Model 7002,
the slot designator can be from 1 to 10 since there are 10
slots.
To be consistent with Model 7001/7002 operation, the slot
designator and channel are separated by an exclamation
point (!). Some examples of CHANNEL assignments are as
follows:
CHANNEL 1!1 = Slot 1, Channel 1
CHANNEL 2!40 = Slot 2, Channel 40
CHANNEL 6!23 = Slot 6, Channel 23
CHANNEL 10!36 = Slot 10, Channel 36
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Figure 3-3
Display organization for input and output channels