Rockwell Automation 2706 DL40 HARDWARE USER MANUAL - Manual (Page 88)

Chapter 9
Using the Parallel Port
9 – 4
Table 9.E
Sample value obtained by summing the BCD value of each data line’s logic level
Data Line Logic Level Value
D0
D1
D2
D3
D4
D5
D6
D7
D8
D9
D10
D11
D12
D13
D14
D15
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
Logic 1
Logic 0
Logic 1
Logic 0
Logic 0
Logic 0
Logic 1
Logic 0
Logic 1
Logic 0
Logic 1
Logic 0
Logic 1
Logic 0
Logic 1
Logic 0
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
1
0
4
0
0
0
40
0
100
0
400
0
1000
0
4000
0
Sum of all values 5545
Adding the values of the individual data lines provides the value being
entered, in this case 5545.
Each parallel input interprets two voltage levels: ON or OFF . There is also a
third state which should be avoided, an “I don’t know” or “indeterminate”
state. The “indeterminate” state occurs when the voltage is between the ON
voltage range and the OFF voltage range. Table 9.F lists the voltage levels
and their logic values.
Table 9.F
Input Voltage Ranges and Their Logic Values
Voltage Range High True Logic Low True Logic
0 – 0.8 VDC 0 (OFF) 1 (ON)
0.8 – 3.5 VDC Indeterminate Indeterminate
3.5 – 24 VDC 1 (ON) 0 (OFF)
You can select either the High True or Low True Logic using the Offline
Programming Software.
Note: You can use 120 volt AC/60 Hz input voltages if two Catalog Number
2706-NG2 Input Converters are used.
The parallel port is compatible with Allen-Bradley’s DC Output Modules
(Catalog No. 1771-OB, 1746-OB8, or 1746-OB16) and AC Output Module
(Catalog No. 1771-OA). Two 2706-NG2 AC input converters are required
Logic Voltage Levels