ADIS16204_07 AD [Analog Devices], ADIS16204_07 Datasheet - Page 19

• Manufacturer Part Number: ADIS16204_07
• Description: Programmable High-g Digital Impact Sensor and Recorder
• Manufacturer: AD [Analog Devices]

Table 29. Alarm and Event Capture Configuration Registers
Register
ALM_CTRL
ALM_CTRL
ALM_CTRL
ALM_MAG1/
ALM_MAG 2
ALM_MAG1/
ALM_MAG 2
CAPT_CFG
CAPT_CFG
CAPT_CFG
COMMAND
COMMAND
COMMAND
COMMAND
COMMAND
MSC_CTRL
SMPL_PRD
Table 30. ALM_CTRL Register Definition
Address
0x29, 0x28
Table 31. ALM_CTRL Bit Descriptions
Bit
15:12
11:8
7
6
5
4
3
2
1
0
Value
0000
0001
0010
0011
0100
0101
1000
Parameter/Function
Alarm trigger source
Capture buffer triggers
Digital alarm output
Alarm trigger levels
Alarm trigger directions
Capture data sources
Capture buffer size
Pretrigger data size
Reset capture pointer
Clear capture buffer
Clear capture flash
Clear buffer full flag
Save captured data to
nonvolatile flash
Autosave captured
data to nonvolatile flash
Sample rate
Default
0x0000
Description
Trigger source selection, Alarm 2
Trigger source selection, Alarm 1 (See Alarm2)
Not used
Capture trigger activation, Alarm 2
Not used
Capture trigger activation, Alarm 1
Not used
Alarm indicator, using DIO1/2
Alarm indicator polarity
Alarm indicator line selection
1 = enabled, 0 = disabled
1 = enabled, 0 = disabled
Disable
Power supply
X-acceleration
Y-acceleration
Auxiliary ADC
Temperature sensor
XY RSS acceleration
1 = enabled, 0 = disabled
1 = active high, 0 = active low
1 = DIO2, 0 = DIO1
Format
N/A
Default Setting
None
Disabled
Disabled
0
Less than
1: X acceleration
2: Y acceleration
1024 samples
128 samples
N/A
N/A
N/A
N/A
N/A
Disabled
4096 SPS
Access
R/W
Rev. 0 | Page 19 of 24
Table 32. ALM_MAG1 Register Definition
Address
0x21, 0x20
Table 33. ALM_MAG2 Register Definition
Address
0x23, 0x22
Table 34. ALM_MAG1/ALM_MAG 2 Bit Designations
Bit
15
14
13:0
Event Capture Overview
The ADIS16204 also provides a dual-channel, capture function.
Figure 24 provides an example of a captured waveform. A dedi-
cated set of programmable control registers govern the operation
of this function, controlling the data source: trigger settings
(level, direction and data source), memory depth, pretrigger
data length, and data storage. In systems that require specific
event monitoring, this feature simplifies system integration by
reducing the burden on the system’s processor. One convenient
feature is the fact that the trigger source does not have to be the
data that is captured.
Event Capture Configuration
The event capture buffers use the alarms as their trigger source.
Therefore, the first two configuration steps are the same. After
setting the trigger data source(s) and threshold(s), follow these
steps to complete the event capture setup:
1. Program The Data Source To Capture.
This requires a single write cycle, to configure the upper byte of
the CAPT_CFG register. For example, use the following pseudo
code to set X acceleration and Y acceleration as the data sources
for Capture Buffer 2 and Capture Buffer 1 respectively:
•
Write 0x23 to Address 0x39 [CAPT_CFG].
–10
–15
–20
20
15
10
–5
5
0
0
Description
Comparison polarity
Not used
Data bits: format matches source data format
(see Table 5 and Table 6)
PRE-TRIGGER
1 = greater than, 0 = less than
LENGTH
100
DATA
Default
0x0000
Default
0x0000
Figure 24. Event Capture Example
200
300
SAMPLE –
DATA SOURCE: Y-AXIS ACCELERATION
TRIGGER THRESHOLD: 7.4g
400
500
f
Format
N/A
Format
N/A
s
= 4096SPS
600
700
ADIS16204
800
Access
R/W
Access
R/W
900
1000