Configuration Of Usb Disk; Saving Data To Usb Disk; Hdf5 File Hierarchy - VTI Instruments EX1401 User Manual

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In order to safely remove a USB disk, first abort any measurement that is saving data to the disk,
then navigate to the "USB at sda1" (assuming the device is mounted at sda1) page of the LCD menu
and hold the MENU button for 5 seconds. Upon releasing the MENU button, the screen should
change to read "Safe to remove" in place of the volume label on the second row. If an error is
displayed instead, the disk is still in use by an active measurement.
C USB D
ONFIGURATION OF
In order to configure the data logger session, the user must place a device configuration file in the
top-level directory of the attached USB Memory Disk. It will be the same format used internally by
the Configuration.StoreCurrent API. The user can construct this file manually or use the
Configuration.SaveConfigurationToStorageDevice method to save the current instrument
configuration to the attached USB Memory Disk. This and the other storage device configuration
methods all take the repeated capability name of a StorageDevice item as an argument, and act on
the file config.json within that device. The StorageDevice item must have the Enabled property set
to true before the configuration is saved to that storage device.
S D USB D
AVING ATA TO
A new repeated capability, Storage.Devices, has been added to the VTEXDigitizer/VTEXDsa
drivers to represent the attached storage devices. The data will be saved to any enabled storage
devices in the HDF5 format. This API allows multiple storage devices to be enabled at the same
time, or for VRT streaming to be enabled alongside them. In that case, identical data will be sent to
all enabled devices and streaming sockets. FIFO polling via Measurement.Read, however, is only
supported when all streaming protocols and storage devices are disabled, as the data is removed
from the FIFO when it is sent to the storage devices and streaming sockets.
HDF5 F H
ILE IERARCHY
HDF5 is a hierarchical file format based on string group names, which contain datasets, which are
arrays of like key-value pair collections. The root group of the HDF5 file will be "inst0", which is
the same as the slot name of the instrument. This will contain one group per channel, named the
same as that channel, "CH1" to "CH16", as well as "DIO". Each channel group will contain one
dataset for each VRT packet type. HDF5's Packet Table type will be used to pack the raw VRT
data into these datasets. Attributes will be set on the "inst0" and channel groups to indicate the
instrument's configuration state at the time that the measurement was initiated.
▪
inst0 (group)
•
96
ISK
ISK
<channel> (group)
o
IF_MEAS_INFO (dataset)
▪
Packet info - The upper 16 bits of the VRT Header word
▪
Packet size - The total number of 32-bit words in the packet
▪
Stream ID - The VRT Stream identifier
▪ OUI - VTI's IEEE Organizationally Unique Identifier
▪
Information class code - The VRT information class identifier
▪
Packet class code - The VRT packet class identifier
▪
Time seconds - The seconds portion of the packet timestamp
▪
Time picoseconds upper - The upper 32 bits of the
picoseconds portion of the packet timestamp
▪
Time picoseconds lower - The lower 32 bits of the
picoseconds portion of the packet timestamp
▪
Context Indicator Field - A mask indicating which items are
included in Context Fields
▪
Context Fields - A list of 32-bit words comprising the data
payload of the context packet
EX1401 Operation of Data Logger