LabJack U12 - Page 50

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()
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],
50