NOVUS Web Server – WS10 User Manual
Page 11
Web Server – WS10
NOVUS AUTOMATION
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LOCAL INPUTS CALIBRATION
Before using a local input as analog input, it must be calibrated. The local inputs have a 10 bits resolution and a measurement range from 0 to 5V
or 0 to 20mA. The calibration procedure allows configuration of the measured value range, to achieve the desired result in engineering units.
Calibration is configured in 2 parameters for each channel on the LOCALIO.CFG file: CalLow and CalHigh. During calibration the values of these
parameters need to be changed using the described FTP procedures. Remember to reboot the WS10 after the transfer of a new configuration file.
The measurement result of each channel can be viewed using the browser to display the default HTML file installed on the WS10.
The goal of the calibration procedure is to get the minimum and maximum desired values when the minimum and maximum signals are applied to
each input. On the following procedure, this indication limits are identified as ResultLow and ResultHigh.
The calibration procedure shoul be executed to each analog input, following the next steps.
•
Configure the J1 to J5 jumpers according to the type of signal – V or mA.
•
Edit the LOCALIO.CFG file to set the initial values for the calibration parameters: CalLow = 0 and CalHigh = 1023. Transfer the file to
the WS10 and reboot.
•
Apply the lowest signal value to the input (for example, 0V for a 0-5V signal or 4mA for a 4-20mA signal).
•
Check the measurement of the input – This value is the ADLow.
•
Apply the highest signal value to the input (for example, 5V for a 0-5V signal or 20mA for a 4-20mA signal).
•
Check the measurement of the input – This value is the ADHigh
•
Calculate the first calibration parameter of the channel – CalLow:
(
) (
)
(
)
sultLow
Re
sultHigh
Re
sultLow
Re
ADHigh
sultHigh
Re
ADLow
CalLow
−
Ч
−
Ч
=
•
Calculate the second calibration parameter of the channel – CalHigh:
(
)
sultHigh
Re
ADHigh
sultHigh
Re
CalLow
CalHigh
Ч
+
−
Ч
=
1023
1023
•
Edit the calibration parameters CalLow and CalHigh on the calibrated channel section of the LOCALIO.CFG. Transfer the file to the
WS10 and reboot.
•
Check the calibration result on the extreme input values and at least one intermediate value.
•
Repeat the above procedure for each analog input.
If CalLow or CalHigh values result out of the –32768 to +32767 range, the desired calibration is not achievable. Try different values for ResultLow
and ResultHigh.
PREDEFINED TAGS OF THE WS10
In addition to the user defined tags, the WS10 has a set of predefined tags, listed on the following table.
Internal Tag name
Description
_VER
Integer value containing the firmware version of the WS10. Read only.
_BOOT
WS10 reboot. Write 1 to this tag to force the reboot. Write only.
_DAY
Day value of the internal real time clock. Read/Write.
_MONTH
Month value of the internal real time clock. Read/Write.
_YEAR
Year value of the internal real time clock. Read/Write.
_HOUR
Hour value of the internal real time clock. Read/Write.
_MIN
Minutes value of the internal real time clock. Read/Write.
_SEC
Seconds value of the internal real time clock. Read/Write.
_LOG
Identify the content of the data logger function. Used on the configuration of the email or of the data delivery functions, to
enable transmission of the data logger memory content. Read only
_LOG_E
Identify the content of the data logger function. Used on the configuration of the email or of the data delivery functions, to
enable transmission of the data logger memory content, followed by an automatic log erase. Read only
REFERENCE TO THE _INTERNAL_ DEVICE TAGS
The _INTERNAL_ device contains all internal tags of the WS10:
•
Predefined tags
•
Tags assigned to the local inputs and outputs
•
Tags assigned to memory registers
To reference internal tags on the creation of HTML files and other configurations, use the syntax exemplified below:
_INTERNAL_/_day
_INTERNAL_/MyOUT