Pacific Research Solutions PET-820 User Manual
Page 40
Pacific Research
PET-820 User Manual
Page 39
4.6.9
SELECT ADC MODE, SINGLE / DIFFERENTIAL ENDED INPUT
This feature allows the analog inputs to be used in a differential mode. Keep in mind that neither of the high or low input
signals should exceed 5.50 volts in reference to ground. (Refer to Figure 5.1 in this manual for information on connecting
signals for the differential mode).
At this point we advise not to use the differential mode because it has not been completely tested. This mode will be tested
and updated prior to the next software release.
COMMAND CODE:
78
PROGRAM SYNTAX:
78 [Data] #
READ BACK SYNTAX:
78 #
WHERE:
Data = Zero or non zero, Zero = Single ended mode, Non Zero = Differential mode
EXAMPLE:
78 1 # = Select differential ended input mode
DEFAULT:
0, Single ended
4.6.10 SELECT ADC MODE, HIGH / LOW RANGE
This feature allows you to select a voltage range to use for all input of the analog option. The high range is +/-4.095 volts in
1 millivolt increments and the low range is +/-0.4095 volts in 100 microvolt increments. Regardless of which range that is
used, do not supply an analog voltage greater than 5.50 volts to any of the inputs.
COMMAND CODE:
79
PROGRAM SYNTAX:
79 [Data] #
READ BACK SYNTAX:
79 #
WHERE:
Data = Zero (0) or Non Zero (1-9),
Zero = Low range +/- 0.4095 volts
Non Zero = High range +/- 4.095 volts
EXAMPLE:
79 1 # = Select low range
DEFAULT:
1, High range
4.6.11 ANALOG TO DIGITAL CONVERTER INITIALIZATION
This command will reinitialize only the systems characteristics relating to the analog input option. The reset values are the
original factory default settings. Caution when using this command, any changes to the operation of the analog input option
or new characteristics that have been stored will be lost. In order to operate this command the user must include the unit
serial number. This is a 8 digit number that is identified on top of the program EPROM and on the back side of the circuit
board. The program authorization is not required to execute this command. Caution should be taken in identifying to
unqualified users the unit serial number and use of this command.
COMMAND CODE:
84
PROGRAM SYNTAX:
84 [Serial No.]
4.6.12 ANALOG SCALING (ENGINEERING UNITS)
This feature has been provided for the purpose of scaling an analog input value to engineering units or some meaningful data
for the user. As an example, an output from a pressure transducer may range from 0 to 1.00 volt indicating 0 to 200.0 PSI.
By properly setting the factorial, decimal point position, round off point, and identifier the PET-820 will now read this value
as "Zero point Zero P S I" through "Two hundred point zero P S I". The following commands in this sub section may be used
to set up engineering units to fit your application.