Raritan EMX2-111, User Manual

Page: 257 / 565

Chapter 6: Using the Web Interface
245
Setting Data Logging
The EMX can store 120 measurements for each sensor in a memory
buffer. This memory buffer is known as the data log. Sensor readings in
the data log can be retrieved using SNMP.
You can configure how often measurements are written into the data log
using the Measurements Per Log Entry field. Since the EMX internal
sensors are measured every second, specifying a value of 60, for
example, would cause measurements to be written to the data log once
every minute. Since there are 120 measurements of storage per sensor,
specifying a value of 60 means the log can store the last two hours of
measurements before the oldest one in the log gets overwritten.
Whenever measurements are written to the log, three values for each
sensor are written: the average, minimum and maximum values. For
example, if measurements are written every minute, the average of all
measurements that occurred during the preceding 60 seconds along
with the minimum and maximum measurement values are written to the
log.
Note: The EMX device's SNMP agent must be enabled for this feature to
work. See
Enabling and Configuring SNMP
(on page 284). In addition,
using an NTP time server ensures accurately time-stamped
measurements.
By default, data logging is enabled. You must have the "Administrator
Privileges" or "Change EMD Configuration" permissions to change the
setting.
To configure the data logging feature:
1. Choose Device Settings > Data Logging.
2. To enable the data logging feature, select the "Enable" checkbox in
the General Settings section.
3. Type a number in the Measurements Per Log Entry field. Valid range
is from 1 to 600. The default is 60.
Tip: Type a large number in this field when there are a large number
of environmental sensors connected. This is because the sensor
update interval becomes longer. See
Information about Update
Interval
(on page 246).
4. Verify that all sensor logging is enabled. If not, click Enable All at the
bottom of the page to have all sensors selected.

You can also click the topmost checkbox labeled "Logging
Enabled" in the header row of each section to select all sensors
of the same type.