DIFFERENTIAL CONDUCTANCE PROTOCOLS
======================================
Started 2013 June 12 A.Stummer
Last revised 2014 Dec 2 A.S. (changed 90/270� to normalized phase angle, changed "S" to all settings, changed "A" to ASCII)
All communication between host and unit is UDP/IP with DHCP and port 37829.
Generally, the host sends a command and the unit reacts.
Loss of communication between host and unit will shutdown unit outputs.
HOST TO UNIT COMMANDS
---------------------
Cmd Size Description
--- ---- -------------------------
H 1 Heartbeat, unit will echo heartbeat. Loss of HB will stop unit from running
M 1 Measure all voltages and currents at the set phase angle
S 1 Request all settings then reset ADC overflow flags
D 7 Set the DC voltage, normalized to �1
Byte 1: 'D', header for DC voltage command
2: '+' or '-', polarity
3: '0' or '1', units (if 1 then must be 1.000)
4: '.' always
5: tenths of output
6: hundredths of output
7: thousandths of output
F 5 Set the Frequency in integer Hz, 25 to 1000Hz
Byte 1: 'F', header for frequency command
2: '1' or '0', thousands of Hz
3: hundreds of Hz
4: tens of Hz
5: units of Hz
A 4 Set the AC voltage level (0-255, unitless)
Byte 1: 'A', header for AC voltage command
2: hundreds
3: tens
4: units
P 4 Set the Phase angle for measurement (0-359�)
Byte 1: 'P', header for phase angle command
2: hundreds
3: tens
4: units
Q 5 Set the Number of samples to average
Byte 1: 'Q', header for averaging count command
2: thousands
3: hundreds
4: tens
5: units
G 3 Set the AC-Voltage gain
Byte 1: 'G', header for AC voltage gain command
2: "1" or "3" for gain x1 or x3
3: decade gain, power of 10 ("0", "1", "2") for gain: 1, 10, 100
C 3 Set the AC-Current gain
Byte 1: 'C', header for AC current gain command
2: "1" or "3" for gain x1 or x3
3: decade gain, power of 10 ("0", "1", "2") for gain: 1, 10, 100
EXAMPLES (exclude quotes):
"D+0.500" or "D0.5000" or "D.50000" DC normalized voltage of 50%
"F0050" AC frequency 50Hz, can also be "F 50" or "F 50 "
"P123" Measure at 123� phase angle
"G32" AC voltage gain is 300
"A2"+0x00 AC voltage output is 50 (the "2" is ASCII 0x32 or decimal 50, plus 0x00)
"Q0100" Average over 100 samples
UNIT TO HOST PACKETS
---------------------
Cmd Size Description
--- ---- -------------------------
H 1 Heartbeat, echoed when received from host
V - Version, as per following:
First byte "V"
Then Rabbit version string (e.g. "1.2.3")
Then a \n char (0x0A)
Then unit name (e.g. "Diff Con")
D 21 All four ADC raw values (unsigned 16-bit)
Byte 1: 'D', header for ADC values
2-6: DC voltage (00000 to 65535)
7-11: AC voltage (00000 to 65535)
12-16: DC current (00000 to 65535)
17-21: AC current (00000 to 65535)
S 48 Send all settings
Byte 1: 'S', header for sending all settings
2-8: Normalized DC voltage (format same as command "D")
9: Space
10-14: Frequency (format same as command "F")
15: Space
16-19: Phase angle (format same as command "P")
20: Space
21-25: Samples to average (format same as command "Q")
26: Space
27-29: AC voltage gain (format same as command "G")
30: Space
31-33: AC current gain (format same as command "C")
34: Space
35-38: AC voltage level (format same as command "A")
39: Space
40: DC-V ADC saturated low ("0"=okay, "1"=saturated)
41: DC-V ADC saturated high ("0"=okay, "1"=saturated)
42: AC-V ADC saturated low ("0"=okay, "1"=saturated)
43: AC-V ADC saturated high ("0"=okay, "1"=saturated)
44: DC-I ADC saturated low ("0"=okay, "1"=saturated)
45: DC-I ADC saturated high ("0"=okay, "1"=saturated)
46: AC-I ADC saturated low ("0"=okay, "1"=saturated)
47: AC-I ADC saturated high ("0"=okay, "1"=saturated)
48: Space
EXAMPLES (exclude quotes):
"D3725 335984567814678" Data from ADCs are DC voltage 3725 (note space), AC voltage 33598, DC current 45678, AC current 14678.
"SD+0.000 F1000 P000 Q0010 G10 C10 A00 00000000 " is the default cold boot settings