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SVM2608 Programming
41
M
ICROPROCESSOR
C
OMMANDS
Unless otherwise specified, commands are issued to each channel’s
command register
. After
issuing a command, the user must wait until the command is executed before issuing a new
command to the same channel. The module sets the Command Register to all zeros when a
command is finished executing. Issuing a new command before a command completes will yield
unpredictable results and may place the board into an unknown state. It is acceptable, however, to
issue a command to a different channel without waiting for the current channel to finish execution.
Measurement Commands
The following is a list of the measurement commands:
NOTE
The currents generated by the current sources are listed here for REFERENCE only. The board is
not designed to be a
precision
current source. These current sources are used for resistance
measurements, but all the calculations are adjusted to the internally calibrated values.
0x0001 = Peak Voltage Calculation
0x0002 = DC Voltage Calculation
0x0003 = RMS Voltage Calculation
0x0004 = Peak-to-Peak Voltage Calculation
0x0005 = 100
Ω
Range Resistance Measurement (2-wire)
0x0006 = 1 k
Ω
Range Resistance Measurement (2-wire)
0x0007 = 10 k
Ω
Range Resistance Measurement (2-wire)
0x0008 = 100 k
Ω
Range Resistance Measurement (2-wire)
0x0009 = 1 M
Ω
Range Resistance Measurement (2-wire)
0x000A = Auto-range Resistance Measurement (2-wire)
0x000B = 100
Ω
Range Resistance Measurement (4-wire)
0x000C = 1 k
Ω
Range Resistance Measurement (4-wire)
0x000D = 10 k
Ω
Range Resistance Measurement (4-wire)
0x000E = 100 k
Ω
Range Resistance Measurement (4-wire)
0x000F = 1 M
Ω
Range Resistance Measurement (4-wire)
0x0010 = Auto-Range Resistance Measurement (4-wire)
0x0011 = Perform Self-Test
0x0012 = 1 V Range Voltage Measurement
0x0013 = 2 V Range Voltage Measurement
0x0014 = 5 V Range Voltage Measurement
0x0015 = 10 V Range Voltage Measurement
0x0016 = 20 V Range Voltage Measurement
0x0017 = 50 V Range Voltage Measurement
(for Channels 0-3 Only)
0x0019 = Auto Range Voltage Measurement
0x001A = Minimum Voltage Calculation
0x001B = Resistance Calculation
0x001C = Set current source for 100
Ω
/ 1 k
Ω
measurement (
≈
2 mA)
0x001D = Set current source for 10 k
Ω
measurement (
≈
0.2 mA)
0x001E = Set current source for 100 k
Ω
measurement (
≈
0.02 mA)
0x001F = Set current source for 1 M
Ω
measurement (
≈
0.002 mA)
0x0020 = Correct setup with calibrations (set offset & gain DACs and calibrated trigger
levels based on calibration values)
0x0021 = 0.5 V Range Voltage Measurement
(for Channels 4-5 Only)