User Manual

PNI Sensor Corporation Doc 1017252 r04
RM3100 & RM2100 Sensor Suite User Manual Page 34 of 45
case only the X axis sensor is being monitored, the ALLX register is set to 0x0A00,
the AULX register is set to 0x1000, and the ADLX register is set to 0x0100.
Table 5-7: Absolute vs. Relative Alarm Mode Example
State Description
MX
Absolute Alarm Mode
Relative Alarm Mode
UL
LL
ALARM
bit
UL
LL
ALARM
bit
Initial State & Measure
0x0F00
0x10000
0x0A00
0
0x10000
0x0A00
0
Perturbation Applied & Measure
0x1100
0x10000
0x0A00
1
0x10000
0x0A00
1
Measure Again
0x1100
0x10000
0x0A00
1
0x12000
0x1000
0
Measure Again
0x1100
0x10000
0x0A00
1
0x12000
0x1000
0
Remove Perturbation& Measure
0x0F00
0x10000
0x0A00
0
0x12000
0x1000
1
Measure Again
0x0F00
0x10000
0x0A00
0
0x10000
0x0A00
0
Measure Again
0x0F00
0x10000
0x0A00
0
0x10000
0x0A00
0
5.3 Initiate a Single Measurement (0x00)
The MagI2C can operate in either a continuous measurement mode or a polling mode. This
section discusses the Single Measurement Command used in a polling mode. See Section 5.2
for operation in continuous measurement mode.
To make a single measurement it is necessary to write the POLL address register, 0x00, and
follow this by the POLL register byte which establishes which axes are to be measured. It is
defined as shown below, where a “1” for PMX, PMY, and/or PMZ indicates the X, Y, and/or
Z axis, respectively, is to be measured. Note that the DRDY line will go HIGH after all
measurements requested in the Single Measurement Command byte have been completed.
Bit #
7
6
5
4
3
2
1
0
Value
0
PMZ
PMY
PMX
0
0
0
0