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Datasheets and User Guides

App Notes

Software & Driver

 

5.1 - AISample

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
}