5.5 - AIBurst [U12 Datasheet]

After receiving a AIBurst command, the LabJack collects 4 channels at the specified data rate, and puts data in the buffer. This continues until the buffer is full, at which time the LabJack starts sending the data to the host. Data is sent to the host 1 scan at a time while checking for a command from the host. If a command is received the burst operation is canceled and the command is executed normally. If the LED is enabled, it blinks at 4 Hz while waiting for a trigger, is off during acquisition, blinks at about 8 Hz during data delivery, and is set on when done or stopped.

Table 5.5-1.

Command
Byte #	Description
0	Bit 7: X
	Bits 6-4: PGA for 1st Channel
	Bits 3-0: MUX command for 1st Channel.
1	Bit 7: X
	Bits 6-4: PGA for 2nd Channel
	Bits 3-0: MUX command for 2nd Channel.
2	Bit 7: X
	Bits 6-4: PGA for 3rd Channel
	Bits 3-0: MUX command for 3rd Channel.
3	Bit 7: X
	Bits 6-4: PGA for 4th Channel
	Bits 3-0: MUX command for 4th Channel.
4	Bits 7-5: Number of scans ( 000 = 1024, 110 = 16)
	Bits 4-3: IO to trigger burst on
	Bit 2: State to trigger on
	Bit 1: Update IO
	Bit 0: LED State
5	Bits 7-4: 1010 (Start Burst)
	Bits 3-0: Bits for IO3 through IO0 States
6	Bit 7: Feature Reports
	Bit 6: Trigger On
	Bits 5-0: AIINTMSB (High 6 bits of sample interval)
7	AIINTLSB (733 = min => ~8192 Hz)


Response
Byte #	Description
0	Bit 7-6: 10 (binary)
	Bit 5: Buffer Overflow if Backlog = 11111, Checksum Error if Backlog = 0
	Bit 4: PGA Overvoltage
	Bits 3-0: Bits for IO3 through IO0 State
1	Bits 7-5: Iteration Counter
	Bits 4-0: Backlog/256
2	Bits 7-4: Most Significant Bits from 1st Channel
	Bits 3-0: Most Significant Bits from 2nd Chanel
3	Least Significant Byte from 1st Channel
4	Least Significant Byte from 2nd Channel
5	Bits 7-4: Most Significant Bits from 3rd Channel
	Bits 3-0: Most Significant Bits from 4th Chanel
6	Least Significant Byte from 3rd Channel
7	Least Significant Byte from 4th Channel

PGA Gain Setting – (Differential Only) 0b000 = 1, 0b001 = 2, 0b010 = 4, 0b100 = 8, 0b101 = 10, 0b110 = 16, 0b111 = 20
Mux Settings – 0b0000 = 0-1 (Differential), 0b0001 = 2-3 (Differential), 0b0010 = 4-5 (Differential), 0b0011 = 6-7 (Differential). Single-Ended readings = 0b1000 + AI Number.

LabJackPython Example

>>> import u12
>>> d = u12.U12(debug=True)
open called
Writing: [0x0, 0x0, 0x0, 0x0, 0x0, 0x57, 0x0, 0x0]
Received: [0x57, 0x0, 0x0, 0x0, 0xff, 0xff, 0x0, 0x0]
>>> d.rawAIBurst()
Writing: [0x8, 0x9, 0xa, 0xb, 0xe1, 0xa0, 0xa, 0x98]
Received: [0x80, 0x0, 0x99, 0x8, 0x2a, 0x99, 0x2c, 0x6]
Received: [0x80, 0x20, 0x99, 0xc, 0x2a, 0x99, 0x2c, 0x4]
Received: [0x80, 0x40, 0x99, 0xc, 0x2c, 0x99, 0x2a, 0x6]
Received: [0x80, 0x60, 0x99, 0xc, 0x2a, 0x99, 0x2c, 0x4]
Received: [0x80, 0x80, 0x99, 0xc, 0x2c, 0x99, 0x2c, 0x6]
Received: [0x80, 0xa0, 0x99, 0x0, 0x2a, 0x99, 0x2c, 0x4]
Received: [0x80, 0xc0, 0x99, 0xc, 0x2a, 0x99, 0x2c, 0x6]
Received: [0x80, 0x0, 0x99, 0xc, 0x2a, 0x99, 0x2c, 0x6]
{
'Channel0': [1.2890625, 1.30859375, ..., 1.30859375],
'Channel3': [1.279296875, 1.26953125, ..., 1.279296875],
'Channel2': [1.46484375, 1.46484375, ..., 1.46484375],
'PGAOvervoltages': [False, False, ..., False],
'IO3toIO0States':
[
<BitField object: [ IO3 = Low (0), IO2 = Low (0),
IO1 = Low (0), IO0 = Low (0) ] >,
<BitField object: [ IO3 = Low (0), IO2 = Low (0),
IO1 = Low (0), IO0 = Low (0) ] >,
...,
<BitField object: [ IO3 = Low (0), IO2 = Low (0),
IO1 = Low (0), IO0 = Low (0) ] >],
'BufferOverflowOrChecksumErrors': [False, False, ..., False],
'Channel1': [1.455078125, 1...., 1.455078125],
'IterationCounters': [0, 1, 2, 3, 4, 5, 6, 0],
'Backlogs': [0, 0, 0, 0, 0, 0, 0, 0]
}