VN-200 User Manual
UM004
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5.12
Synchronization Control
Synchronization Control
Register ID :
32
Firmware :
v0.1 and up
Access :
Read / Write
Comment :
Contains parameters which allow the timing of the VN-200 to be synchronized with
external devices.
Size (Bytes):
20
Example Serial Read
Register Response:
$VNRRG,32,6,0,0,0,6,1,0,100000000,0*6E
Byte
Offset Name
Number
Format
Unit Description
0
SyncInMode
U1
-
Input signal synchronization mode
1
SyncInEdge
U1
-
Input signal synchronization edge selection
2
SyncInSkipFactor
U2
-
Input signal trigger skip factor
4
RESERVED
U4
-
Reserved for future use. Defaults to 0.
8
SyncOutMode
U1
-
Output synchronization signal mode
9
SyncOutPolarity
U1
-
Output synchronization signal polarity
10
SyncOutSkipFactor
U2
-
Output synchronization signal skip factor
12
SyncOutPulseWidth
U4
ns
Output synchronization signal pulse width
16
RESERVED
U4
ns
Reserved for future use. Defaults to 0.
5.12.1
SyncInMode
The SyncInMode register controls the behavior of the SyncIn event. If the mode is set to COUNT, the
internal clock will be used to control the ADC timing. If SyncInMode is set to ASYNC, the ADC loop will
run on a SyncIn event. The relationship between the SyncIn event and a SyncIn trigger is defined by the
SyncInEdge and SyncInSkipFactor parameters. It is very important to note that the VN-200 must always
operate at an internal rate of 200 Hz. If the SyncIn event is used to control the ADC sampling, the SyncIn
event must be kept always at 200 Hz. If set to ASYNC, the VN-200 will output asynchronous serial
messages upon each trigger event.
Table 32 – SyncIn Mode
Mode
Pin
Value
Description
COUNT2
SYNC_IN_2
0
Count number of trigger events on SYNC_IN_2 (pin 15).
ADC2
SYNC_IN_2
1
Start ADC sampling on trigger of SYNC_IN_2 (pin 15).
ASYNC2
SYNC_IN_2
2
Output asynchronous message on trigger of SYNC_IN_2 (pin 15).
COUNT
SYNC_IN
3
Count number of trigger events on SYNC_IN (pin 22).
ADC
SYNC_IN
4
Start ADC sampling on trigger of SYNC_IN (pin 22).
ASYNC
SYNC_IN
5
Output asynchronous message on trigger of SYNC_IN (pin 22).
GPS_PPS
GPS_PPS
6
Count number of trigger events on GPS_PPS (pin 24).
The SyncIn pin is set by default to operate on pin 22. For reverse compatibility with existing
VectorNav products it is possible to remap the SyncIn pin to operate on pin 15 instead. For
future designs it is recommended that pin 22 is used for the SyncIn feature.
