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MPS4232
Section 3: Operation
Max Delay = (1/MPS Rate) * (Max Frames in Buer) / 2)
Max Delay = (1/MPS Rate) * 32768 / 2)
Max Delay = 16384 / MPS Rate
Note: The buer size in the MPS4232 is 32768 frames.
However, to handle delays in the network connecon only
half should be used as a target delay. Thus 16384 frames
are the maximum frames to hold in the buer.
The MPS’s soware incorporates a zero oset correcon
feature (Quick Zero or CALZ). This feature provides a simple
and quick means to correct for the minor zero dri prob-
lems inherent to piezoresisve sensors.
Because the MPS4232 does not have a calibraon valve,
the CALZ must be performed in a “wind-o” state (no
pressure applied to the module). At that point, with the
sensor at its natural zero dierenal state, any oset can
be read and recorded. This can then be factored into the
engineering unit conversion and mathemacally removed
automacally within the MPS soware. Quick Zero calibra-
ons can be performed in under 10 seconds.
Due to the nature of the piezoresisve sensors used in
the MPS modules, it is recommended that a quick zero
calibraon be performed at least daily. Performing a quick
zero more oen will not cause any problems and is highly
encouraged. There are no issues using the quick zero cali-
braon each me before data is collected. Keep in mind, if
the temperature of the module changes more than 5°C, a
fresh quick zero should be performed.
Zero oset correcons may become obsolete aer several
hours or aer the module has changed temperatures.
The MPS is compliant with IEEE1588v2 Precision Time
Protocol (PTP). The MPS’s PTP engine can be congured as
follows:
• Disabled
• Enabled as a PTP slave device
• Enabled as a PTP master device
When congured as a PTP slave device, the MPS will listen
for PTPv2 packets being mulcasted on the network. This
allows for the MPS’s internal me and date to be set and
synchronized when a PTP Grandmaster is acve on the
same network. This synchronizaon will also adjust the
internal scan rate of the module to pace with the PTP
Grandmaster me.
When the MPS4200 is congured as a PTP master device,
the MPS will mulcast PTPv2 packets over the network,
similar to a PTP Grandmaster. The MPS will use its internal
me and date when mulcasng these packets for synchro-
nizaon. The MPS congured as a PTP master allows other
PTP enabled Scanivalve devices to be synchronized using
the internal me and date of the ‘master’ MPS device. This
synchronizaon on ‘slave’ devices will adjust the internal
scan rate of the ‘slaves’ to pace with the PTP Master.
Note: Only one PTP Grandmaster or PTP master can be
present on a network at any given me.
When the MPS is enabled as a ‘slave’ PTP device, the
MPS requires that announce packets are mulcast on the
network.
Whether PTP is enabled or disabled, the GETTIME
command will retrieve the current internal me of the
MPS. When the MPS’s PTP engine is disabled or enabled as
a PTP master, the MPS’s me and date can be manually set
using the SETTIME command.
Other PTP related commands, including PTP stascal
informaon, debug output, and seng the UTC oset, can
be referenced in the PTP Commands secon under Secon
5: Soware.
The IEEE1588 protocol allows MPS4200 units to start scan-
ning at a preset me and date while keeping their data
samples me synchronized. This allows a user to synchro-
nize the scan start me across mulple units. A scan
start me and date in the future can be congured in the
MPS4200 using the Scan Start Date (SSD) and Scan Start
Time (SST) variables. Aer a SCAN command is issued, the
MPS will enter scan mode but will not output data. Once
the SST and SSD me has been met (based on the internal
me of the MPS/PTP Time), the me will trigger the MPS to
start releasing frames of data at the set internal rate. If SST
and SSD are set for a me in the past (based on the internal
me of the MPS), a SCAN command will execute a scan and
the MPS will release data immediately.
The following table describes a start scan me with two
MPS4200 units when seng SSD and SST for a me in the
future.
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