OSPD (Overspeed Alarm)¶
The AT@OSPD command is used to set the overspeed detection function. It supports 1 to 4 level thresholds. You can enable only one level or multi-level thresholds. The speed threshold is set to 0, which means that this level of overspeed detection is disabled.
Please follow the order of 1 to 4 to enable multi-level overspeed detection. That is, these 4 speed thresholds should not be used across levels. For example, setting of ‘Speed Threshold 1’ is 50, ‘Speed Threshold 2’ is 0, ‘Speed Threshold 3’ is 90 and ‘Speed Threshold 4’ is 110” is not allowed, because if the ‘Speed Threshold 2’ is 0, then ‘Speed Threshold 3’ and ‘Speed Threshold 4’ should also be 0, and so on.
In addition, when enabling multi-level overspeed detection, the high-level speed threshold must always be greater than the low-level speed threshold, that is: ‘Speed Threshold 1’ < ‘Speed Threshold 2’ < ‘Speed Threshold 3’ < ‘Speed Threshold 4’.
You can obtain overspeed information in real time by enabling the Record 14H. You also can obtain statistical information such as the maximum speed after the overspeed is over by enabling the Record 15H.
Example:
AT@OSPD=gv500cna,,50,30,70,30,90,20,110,10,30,012F$
+ACK:OSPD,123456789012345,8203,3,0,,012F,20210407101530,1234$
AT@OSPD?gv500cna,,0C37$
+QRY:OSPD,123456789012345,8203,3,0,1,1,,50,30,70,30,90,20,110,10,30,0C37,20210407101530,1234$
Parts |
Fields |
Length (Byte) |
Range/Format |
Default |
|---|---|---|---|---|
Head |
Header |
3 |
AT@ |
AT@ |
Command Word |
4 |
OSPD |
OSPD |
|
Leading Symbol |
1 |
= |
= |
|
Password |
8-16 |
gv500cna |
||
Body |
Reserved |
0 |
||
Speed Threshold 1 |
<=3 |
0-400 (km/h) |
50 |
|
Duration 1 |
<=4 |
0-3600 (seconds) |
30 |
|
Speed Threshold 2 |
<=3 |
0-400 (km/h) |
70 |
|
Duration 2 |
<=4 |
0-3600 (seconds) |
30 |
|
Speed Threshold 3 |
<=3 |
0-400 (km/h) |
90 |
|
Duration 3 |
<=4 |
0-3600 (seconds) |
30 |
|
Speed Threshold 4 |
<=3 |
0-400 (km/h) |
110 |
|
Duration 4 |
<=4 |
0-3600 (seconds) |
30 |
|
Exit Alarm Validity |
<=4 |
0-3600 (seconds) |
30 |
|
Tail |
Sequence Number |
4 |
0000-FFFF (‘0’-‘9’, ‘A’-‘F’) |
|
Tail |
1 |
$ |
$ |
Speed Threshold 1
The threshold for first level overspeed alarm. If the current speed of vehicle exceeds the value set by ‘Speed Threshold 1’ and is maintained for a period of time defined by ‘Duration 1’, the overspeed alarm (Overspeed Alarm 1) will be triggered. If set to 0, it means that this threshold is disabled.
Duration 1
The duration for first level overspeed alarm.
Speed Threshold 2
The threshold for second level overspeed alarm. If the current speed of vehicle exceeds the value set by ‘Speed Threshold 2’ and is maintained for a period of time defined by ‘Duration 2’, the overspeed alarm (Overspeed Alarm 2) will be triggered. If set to 0, it means that this threshold is disabled.
Duration 2
The duration for second level overspeed alarm.
Speed Threshold 3
The threshold for third level overspeed alarm. If the current speed of vehicle exceeds the value set by ‘Speed Threshold 3’ and is maintained for a period of time defined by ‘Duration 3’, the overspeed alarm (Overspeed Alarm 3) will be triggered. If set to 0, it means that this threshold is disabled.
Duration 3
The duration for third level overspeed alarm.
Speed Threshold 4
The threshold for fourth level overspeed alarm. If the current speed of vehicle exceeds the value set by ‘Speed Threshold 4’ and is maintained for a period of time defined by ‘Duration 4’, the overspeed alarm (Overspeed Alarm 4) will be triggered. If set to 0, it means that this threshold is disabled.
Duration 4
The duration for fourth level overspeed alarm.
Exit Alarm Validity
When the terminal is in alarm state, if the terminal detects that the speed below all thresholds and the duration reaches this value, the terminal will exit alarm state.