Reducing host output requirements – Rockwell Automation 2706 DL20 SERIES G USER MANUAL User Manual
Page 86
Chapter 7
The Parallel Port
7–14
If messages don’t contain variable data, the number of outputs can be
reduced. Since no variable data is transferred, both strobe lines are always
zero, or always one. In addition, some data lines (D0 - D9) could be
eliminated depending on the highest message number used.
Figure 7.3 illustrates this method.
Figure 7.3
11 Ouput Configuration
+
-
D9
D8
D6
D5
D4
D3
D2
D1
D0
MS0
MS1
GND
11A
11B
12
13
14
15
16
17
18
19
21
20
23
Terminal
Number
Terminal Block
Designation
Power Supply
5-30 VDC
(Observe DC
Polarity)
PC Outputs (11)
D7
You can further reduce the output requirements by tying the strobe lines high
as shown in Figure 7.4
Figure 7.4
10 Output Configuration
Tie Together
For HIGH
TRUE Logic
Only
+
-
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
MS0
MS1
GND
11A
11B
12
13
14
15
16
17
18
19
21
20
23
Terminal
Number
Terminal Block
Designation
Power Supply
5-30 VDC
(Observe DC
Polarity)
PC Outputs (10)
Reducing Host
Output Requirements