This function reads from 4 analog inputs. It can also toggle the status LED and update the state of the IOs.
Table 5.1-1.
|
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 7-2: XXXXXX |
|
|
Bit 1: Update IO |
|
|
Bit 0: LED State |
|
5 |
Bit 7-4: 1100 (Command/Response) |
|
|
Bit 3-0: Bits for IO3 through IO0 States |
|
6 |
XXXXXXXX |
|
7 |
Echo Value |
|
|
|
|
|
|
|
Response |
|
|
Byte # |
Description |
|
0 |
Bit 7: 1 |
|
|
Bit 6: 0 |
|
|
Bit 5: X |
|
|
Bit 4: PGA Overvoltage |
|
|
Bits 3-0: Bits for IO3 through IO0 States |
|
1 |
Echo byte 7 from Command |
|
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.rawAISample()
Writing: [0x8, 0x9, 0xa, 0xb, 0x1, 0xc0, 0x0, 0x0]
Received: [0x80, 0x0, 0x99, 0xb, 0x28, 0x99, 0x2c, 0x5]
{
'IO3toIO0States':
<BitField object: [ IO3 = Low (0), IO2 = Low (0),
IO1 = Low (0), IO0 = Low (0) ] >,
'Channel1': 1.4453125,
'Channel3': 1.2744140625,
'Channel2': 1.46484375,
'PGAOvervoltage': False,
'Channel0': 1.3037109375,
'EchoValue': 0
}