Scanivalve MPS4232, Руководство по аппаратному и программному обеспечению

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16
MPS4232
Section 3: Operation
Scanning
Once the MPS module has been installed, powered on and
allowed to thermally stabilize, data can be collected. There
are several configuration variables that control how the
MPS module samples pressure and how the data is output.
Scan Rate
The scan rate is controlled by the variable: RATE . Rate
is expressed in Hertz (Hz), which can be described as
samples per channel per second, or more simply, frames
per second. Because the MPS has one analog-to-digital
converter per transducer, all pressure samples per channel
will be taken synchronously.
Example: If rate is set to 10Hz, the MPS will sample a pres -
sure value from each channel every 0.1 seconds. This data
is packaged into a ‘frame of data‘ and output to the config -
ured destination.
Note: Max scan rates can be limited based on data destina -
tion, format, and configurations. See Appendix C, Table 1
for all scan rate limitations.
Scan Duration
The length of the scan, or number of frames output per
scan, is controlled by the variable: FPS . A frame of data
typically consists of a frame number, time stamp, and one
averaged pressure and temperature sample for each sensor
in the MPS.
Example : If frames per second is set to 100, and the scan
rate is set to 10Hz, the MPS will output 100 frames of data
at 10Hz. This scan will last 10 seconds and only 100 frames
of data will be output. The scan will end when 100 frames
are output.
Example : If frames per second is set to 0, and rate is set to
5Hz, the MPS will output data at 5Hz indefinitely. The scan
must be stopped manually by the user.
Scan Data Format
The data output for ASCII and Binary data collection is
controlled by the variable: FORMAT . Format is split into
three sections; Telnet, FTP/UDP, and Binary Server.
Example: If format is set to C (CSV), the MPS will output the
scan data in a Comma Separated Variable ASCII format.
Scan Data Units
The pressure and temperature unit values output in each
frame of data are controlled by the variable: UNITS . The
MPS supports a number of pressure engineering units
including PSI, Pascals, Bar, and more. Temperature is
limited to degrees Celsius.
Example: If units is set to PSI, the pressure values for each
channel will be output in PSI engineering units, and the
temperature for each channel will be in degrees Celsius.
Example : If units is set to RAW, the pressure values for each
pressure and temperature channel will be output in raw
A/D counts (used for troubleshooting).
Starting a Scan
Once the MPS has been configured for scanning, the MPS
will start sampling and outputting data after the SCAN
command is issued to the MPS module. The MPS will then
enter ‘scan’ mode and will output data at the configured
rate until the frames per scan (FPS) term is met or until
the user has manually stopped the scan. Once the scan
has been completed or terminated, the MPS will return to
‘ready’ mode and will be ready for the next command. The
scenario above is an example of a free-run, internal rate
scan ( TRIG 0 ). Data will be output from the MPS module
over the Ethernet connection and can be collected in the
ASCII format.
There are several ways that the MPS can scan and collect
data. These options include:
• Internal rate, software scan triggered
• Internal rate, hardware scan triggered
• External rate, hardware frame triggering
• External rate, software frame triggering
• Internal rate, scan-on-startup
• Internal rate, PTP time triggered
There are several ways that the MPS can output scan data.
These options include:
• ASCII data via TCP or FTP
• Binary data via TCP, UDP, or FTP
These options make the MPS an extremely versatile and
configurable unit. All different scanning and data output
methods will be described in this manual. For more infor -
mation on the commands used in this section, please refer
to Section 5: Software.
Scanning with an External Trigger
The MPS4200 can be configured to scan with an external
hardware or software trigger. This provides a simple means
of synchronizing the data collection between multiple MPS
units or legacy Scanivalve products when a IEEE-1588 PTP
infrastructure is not in place. It also provides a means of
synchronizing MPS scanners with other, third-party equip -
ment that may not be IEEE-1588 PTP compatible.