Description |
Mode of Operation |
ASIC Mode |
1. |
Factory Mode
The factory mode is the mode that allows the TPM sensor to
transmit RF Frames and sample LF more often in the HKMC factory. The TPM
sensor will send normal RF frames in factory mode.
LF sampling will occur every 1 second, to ensure a rapid response on the production line.
Figure 5 shows the state flow of the ASIC from Off mode through Factory mode to Non-Factory mode.
Factory mode is not a normal mode; it operates over the other
customer visible modes to increase the LF sampling rates while the
factory counter is not Zero.
On leaving Off mode the factory counter will be set to 15,
each time the sensor moves from Service mode to stationary mode, the
counter will be decremented.
After Factory mode has expired, the Factory_LF command can be
used to re-enter Factory mode, in which case the factory counter will
be reset to 15.
If Factory mode is no longer required, it is possible to
reset the factory counter, and therefore exit Factory mode by using the
Exit_Factory_LF command.
During 10.8s mode, the sensor will transmit normal RF data
frames every 10.8s. In case of high line sensor, the function code will
indicate rotational direction.
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2. |
Stationary Mode
In normal operation and while the vehicle is not moving the
TPM Sensor will be in STATIONARY mode. In this mode sample and
transmission rates are described below.
STATIONARY mode is excited when the vehicle begins to move and shock sensor input is verified by the ASIC. |
3. |
AL/ALO Mode
Upon detection of motion, an Unknown / Normal function code
is transmitted, then the sensor enters AL Mode (Auto Learn Mode) or ALO
Mode (Auto Location Mode), depending on TPM sensor type (Lowline or
Highline).
During AL mode, the sensor will continue to transmit
Unknown/Normal function codes every 33 seconds for a duration of 16 RF
Blocks ( 1 RF block = 4 RF frames).
During ALO mode the TPM sensor begins to determine which
direction the sensor is rotating – clockwise or anticlockwise. For the
first transmission after the Unknown / Normal function code, the data
block will contain one of three function codes for ALO Mode. If the ASIC
is unable to make a decision concerning rotational direction, then the
sensor shall transmit an Unknown / Normal function code.
During AL/ALO Mode the shock sensors are sampled for motion,
every 10.8 seconds. The pressure and temperature samples also occur
every 10.8 seconds. The transmission rate and duration of AL/ALO Mode is
set to a one block transmission (4 frames) rate every 33 seconds for a
duration of 16 blocks. In ALO Mode rotational direction is acquired
every 10.8 seconds. The transmitted function code is based on all ALO
data since its last transmission.
The AL/ALO mode function flag will be set for the transmission of all valid AL/ALO frames.
If the speed of the vehicle drops below the stationary
threshold and the sensor detects that there is no motion present, then
AL/ALO Mode will be exited and Service Mode will be entered. If Service
Mode exits due to detection of motion and AL/ALO Mode is re-entered then
the AL/ALO Mode continues where it left off i.e. the total AL/ALO
duration of 16 blocks is achieved regardless if Service Mode or Alert
Mode has been entered during that AL/ALO Mode.
If a pressure change (Alert Mode) is detected in AL/ALO Mode
and DP transmissions occur, AL/ALO Mode is suspended until the DP
transmissions finish.
Sensors with ALO mode have 4 configurable options to optimize
the WAL performance based on evaluation with the customer. Sensors
supplied to Hyundai/Kia will have option 2 configured.
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4. |
Service Mode
Service Mode is the period when the TPM sensor has detected
that the vehicle speed has dropped below the stationary threshold.
During this period the pressure and temperature and motion samples occur
every 15 seconds but there are no transmissions, the TPM sensor will
only transmit on a pressure change, DP. The DP transmission will consist
of two blocks (Total of 8 frames) of pressure information transmitted
over a two second period. The duration of Service Mode is 15 minutes
from when the TPM sensor has detected that there is no rolling
detection. If during Service Mode rolling detection is detected again,
the sensor will exit Service Mode and re-enter the mode it was
previously in before it entered Service Mode, AL Mode or Normal Mode.
Every time Service Mode is entered the 15-minute timer is reset. If
Service Mode is exited before the Service Mode timer expires then the AL
Mode counter will not be reset. Upon expiration of Service Mode the AL
Mode counter is reset.
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5. |
Rolling Mode
When AL Mode expires the TPM sensor enters Rolling Mode. In
Rolling Mode the rate of transmissions and rolling detection sampling
are decreased to once every 60s and the rate of pressure and temperature
sampling occur every 15 seconds. For the first 16 blocks of
transmissions after a drive begins the TPM sensor transmits the AL Mode
function codes Clockwise, Anticlockwise or Normal/Unknown. After the 16
blocks of AL information have been transmitted, the TPM sensor will
transmit the Normal/Unknown function code. If the speed of the vehicle
drops below the stationary threshold and the TPM sensor detects that
there is no rolling detection present, then Rolling Mode will be
suspended and Service Mode will be entered.
On entry to Rolling mode the TPM sensor will sample pressure
and do a normal RF transmission with a NORMAL/UNKOWN function code (see
4.1.1.5: Status Byte).
When vehicle speed has dropped below minimum vehicle speed
threshold, the sensor will remain in Rolling mode until the next
scheduled rolling detection sample occurs. Once the rolling detection
sample has confirmed the vehicle speed is below the threshold, the TPM
sensor will enter Service Mode. After the Service Mode period has
elapsed the TPM sensor will exit to STATIONARY Mode. |
6. |
Alert Mode
In Stationary mode, Service Mode or Rolling mode, pressure is
measured at intervals as described above. During the measurement
routine the current pressure value is compared to the previous
transmitted pressure value. If the current pressure sample differs by
greater than 8 counts (>2 psi ) or more from the previous transmitted
pressure value, a RE-MEASURE will occur immediately to ensure the
sample is correct. If a delta P is confirmed the TPM Sensor will
transmit immediately with an Alert status code. If the RE-MEASURE
transmission occurs coincident with a regular transmission, the
RE-MEASURE takes precedence and the regular transmission will be
replaced by the RE-MEASURE transmission.
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7. |
OFF Mode
This is a mode primarily used for shipping and storage of the
TPM sensor units. When the sensor is de-energized (using the Enter_Off
LF command), it shall transmit one last transmission with the Off Mode
function code then enter the Off Mode immediately. When the TPM sensor
is in Off Mode, it shall continue sampling pressure and temperature at
the rate specified in Table 13 of this document but it shall not
transmit any transmission until the TPM sensor is re-energized again.
The TPM sensor can be re-energized using the Normal LF command or when it detects a change in pressure of 19p.s.i. or greater.
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8. |
RF Test Mode
The sensor must enter the RF Test Mode and provide the state
code specified in 4.1.1.5.6of this document upon the presence of an LF
signal with the LF data command “Test_LF” specified in Table 16
below.
The sensor must react (Transmit and provide data) no later
than 700.0 ms after the LF data code has been detected. As soon as the
sensor enters this mode it shall comply with all the sampling and
transmission requirements specified in Table 14 of this document,
regarding this specific mode independent of rotating, stationary, or
service mode.
The sensor shall count the number of frames (each
transmission contains four frames as shown in Table 15 of this document)
it has transmitted since it entered this Mode, and this number shall be
transmitted within the data in each frame as shown in Table 15 below.
The Data transmitted shall be in the format shown in Table 15
below. When the counter for the number of frames reach the value 255
(All of the 8 bits are used), the counter shall reset and restart again
until the sensor exits this mode.
When the sensor exits this mode it shall clear the number of
frames counter. The sensor shall exit this mode upon the presence of a
Normal_LF command as specified in Section 3.3.2 of this document.
The sensor shall start an eight hours timer from the moment
it enters this mode and then shall exit this Mode immediately after the
eight (8.0) hours'' timer expires
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9. |
Continuous Wave (CW) Mode
The TPM sensor must enter the specified CW Mode when it receives the appropriate LF data command ( CW_Low_LF or CW_High_LF ).
The TPM sensor must react (Transmit) no later than 200.0 ms
after the LF data code has been detected. As soon as the sensor enters
this mode it shall start transmitting the specified CW frequency
(Carrier Wave Frequency) of the TPM sensor.
There are 2 CW modes available:
The sensor shall exit this mode upon the presence of a Normal_LF command.
The sensor shall start a four minutes timer from the moment
it enters this mode and then shall exit this Mode immediately after the
four (4.0) minutes timer expires. |