Code: |
AS + 422 |
Symbolic: |
bccOscStart |
This command will try to start an existing variable oscilloscope (or all oscilloscope of the owner) on the connected device. Request parameters are the following:
Offset |
Type |
Label |
Description |
|---|---|---|---|
0 |
U32 |
OWNER |
Owner identification ID |
4 |
U32 |
ID |
Oscilloscope identification ID, or 0xFFFFFFFFF for all owner's oscilloscope. |
8 |
U16 |
FREQ |
Data stream frequency [hz] |
10 |
U32 |
WDT |
Watchdog time [ms] (initial) |
On success, a bccAck is received with the following data:
Offset |
Type |
Label |
Description |
|---|---|---|---|
0 |
U16 |
FREQ |
Applied (real) data stream frequency [hz] |
Notes:
•The device can reply with a different frequency than required. In this case you can accept the new frequency or stop the oscilloscope or try again by changing something in the oscilloscope definition.
On failure, a bccNack is received. Specific errors:
NACK code |
Description |
Extra data |
|---|---|---|
nackNotFound |
Oscilloscope not found |
|
nackIllegalArgs |
Illegal arguments |
U16 Error field 1=Frequency 2=WD time |
After success, you will receive bccData message at applied frequency (or less if device overloaded), with the following data:
Offset |
Type |
Label |
Description |
|---|---|---|---|
0 |
U32 |
ID |
Oscilloscope ID |
4 |
U8 |
NDS |
N. of DS structure |
5 |
DS |
DS0 |
Data of sample 0 |
... |
... |
.... |
Notes:
•The number of samples (NDS) is decided by the connected device, according with applied frequency. For example, if the frequency is 200HZ the device can decide to send each sample with a message at 200HZ or to send two-samples with a message at 100HZ.
This will allow to have high frequency oscilloscope (with few tracks) even over a standard and limited RS232 device.
Each structure DS (data sample) is defines as follow:
Offset |
Type |
Label |
Description |
|---|---|---|---|
+0 |
DBL |
TIME |
Absolute acquisition time [us] |
+8 |
FLT |
VAL0 |
Track 0 value |
+12 |
FLT |
VAL1 |
Track 1 value (opz) |
... |
... |
... |
... |
... |
VAL{NT-1} |
Track NT value (opz) |
Notes:
•The number of effective track values is the same of number of tracks (NT) in oscilloscope creation with bccOscCreate.
•The PID field for data message is set to 0 when oscilloscope is created and it is incremented by one after each data transmission (progressive).
