Rockwell Automation 2706-DXX Dataliner Message Display DL5 Series - Manual (Page 56)

2706-UM001A-US-P
7-6 Using the Parallel Port
Logic Levels The DL5’s parallel port accepts DC inputs of 0-24 volts. These input
voltages can be used to trigger messages or transfer variable (numeric) data.
The DL5 interprets the voltages that are present on the data lines as either a
“High” or “Low” condition. There is also a third state which should be
avoided, an in between or indeterminate state. The indeterminate state
occurs when the input voltage is between the “High” voltage range and the
“Low” voltage range. The voltage ranges that the DL5 interprets as either
“High” or “Low” values depends on whether positive or negative binary
logic has been selected.
The table below lists the voltage ranges and their logic values.
Positive Logic
Level Negative Logic
Level Recognized
Voltage Range
Indeterminate
Voltage Range
High (True) Low (True) 3.5 to 24V DC 0.9 to 3.5V DC
Low (False0 High (False) 0 to 0.9V DC 0.9 to 3.5V DC