Rockwell Automation 2706-DXX Dataliner Message Display DL5 Series - Manual (Page 63)

2706-UM001A-US-P
Using the Parallel Port 7-13
Parallel Port Power Supply
Requirements
The DL5 parallel ports require an input voltage source between 5-24 VDC
with peak-to-peak noise and ripple less than 5% of the input voltage.
Timing Requirements of the
Parallel Port
The DL5 reads (scans) the data lines periodically. You must ensure that the
data is present on the data lines long enough to be read.
Note: Refer to Chapter 9 for a description of the timing requirements for
messages with variable data.
In order to ensure that the data is read, the data must remain on the data
lines for at least 110 milliseconds. After each scan the DL5 saves a copy of
the data that was read. If the next scan reads the same data, the data is
ignored. This feature prevents multiple triggering of the same message.
The figure below illustrates a typical message trigger sequence. Message
#1 is triggered and then message #10 is triggered. In this example, the DL5
is set to accept BCD formatted codes (message or variable).
BCD Message Number Timing Example
!
ATTENTION: To avoid ground loops, the same power supply
that powers the display must be used to supply the parallel port.
D0
D1
D2
D3
D4
D5
D6
D7
D8
D9
D10
D11
D12
D13
D14
D15
110 ms
110 ms
t0 t1 t2 t3