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16.0 CONTRAST RATIO ADJUSTMENT
16.1
The LCD contrast ratio is adjusted for optimum contrast over a large temperature range at
the factory. It may be necessary however to make slight adjustments to the LCD contrast
ratio because of aging and or extreme temperature changes. The contrast ratio
potentiometer (TP1) is located on the back of the Display Module as shown in the drawings
section. Use an adjusting tool and turn the potentiometer clockwise to lighten the contrast
ratio or counterclockwise to darken the contrast ratio.
To set the potentiometer back to the factory setting: with the Display Module at an ambient
temperature of approximately 65°F to 77°F (18°C to 25°C), turn the potentiometer clockwise
until the display contrast ratio is almost too light to read. Turn the potentiometer
counterclockwise 3 to 3-1/2 turns. The display should then be at a desirable contrast ratio.
17.0 DATA LOGGING AND COMMUNICATION OPTIONS
17.1
The DE-2500 controller system contains a data logging feature. Data logging collects
information from the system and keeps track of, or logs, that information over a period of
time. That data is then available through a PC or PLC at port 1, the RS-232 port or port 3,
the RS-485 port.
17.2
NODE NUMBER - The node number is the address of the controller being contacted. This
number is programmed by the terminal program and can be viewed or edited in the menu
screen, refer to section 14.9. A two digit number from 01 to 99 can be used.
17.3
COMMUNICATIONS PARAMETERS - The following must be set in the PC or PLC to
communicate with the controller system:
Baud Rate:
9600
Data Bits: 8
Stop Bits:
1
Parity:
None
17.4
The data logging memory can retain a total of 100 records before writing over the oldest
information. The most current data is always record number one; the next most current is
number two, etc. The oldest information, record 100, is lost when a new record is written.
The logging period is the time between data logs and can be set from 5 minutes to 999
minutes. The logging period must be set in the terminal program. Reference the
programming instructions form DE PI to set the logging period. So for example, if the logging
period is set for 60 minutes and there are 100 records, it would take 100 hours or 4.16 days
before any logged data was overwritten.
A new record is also written when a first fault occurs. If the first fault occurs between the
logging period, the first fault record will be record number one and the next scheduled record
will be number two.