All data (sent and received) is packed in frames.
offset
size
description
0
2
Magic signature (0xCDAB).
2
2
A number of bytes in payload and checksum (N + 2).
4
N
Payload.
4 + N
2
Checksum (C).
The checksum is 16-bit unsigned integer.
C = 2 + N + (sum of bytes in payload)
Payload format for received data:
offset
size
description
0
1
Kind of packet (see below).
1
M
A packet.
Kind of packet:
value
description
0x01
Reply code packet.
0x02
Measurement packet.
0x03
Save packet.
0x04
Record info packet.
0x05
Record data packet.
0x72
Reply data packet (saves count, records count, etc).
It contains 2 bytes.
value
description
0x4B4F
OK (success).
0x5245
ER (error).
A measurement packet has 4 formats:
normal measurement,
relative measurement,
min/max measurement,
peak measurement.
offset
size
description
0
1
Misc byte (see below).
1
1
Misc2 byte (see below).
2
2
Mode word (see below).
4
1
Range byte (see below).
bit(s)
description
1
Packet has aux1 value.
2
Packet has aux2 value.
3
Packet has bargraph value.
4..6
Packet format:
0: normal
1: relative
2: min/max
4: peak
7
Hold (0: off, 1: on).
bit(s)
description
0
Auto range
1
High voltage
3
Lead error
4
Comp mode
5
Record mode
value
mode / submode
0x1111
VAC/normal
0x1112
VAC/normal relative
0x1121
VAC/Hz
0x1131
VAC/peak
0x1141
VAC/low pass
0x1142
VAC/low pass relative
0x1151
VAC/dBV
0x1152
VAC/dBV relative
0x1161
VAC/dBm
0x1162
VAC/dBm relative
0x2111
mVAC/normal
0x2112
mVAC/normal relative
0x2121
mVAC/Hz
0x2131
mVAC/peak
0x2141
mVAC/AC+DC
0x2142
mVAC/AC+DC relative
0x3111
VDC/normal
0x3112
VDC/normal relative
0x3121
VDC/AC+DC
0x3122
VDC/AC+DC relative
0x3131
VDC/peak
0x4111
mVDC/normal
0x4112
mVDC/normal relative
0x4121
mVDC/peak
0x4211
TempC/T1,T2
0x4212
TempC/T1,T2 relative
0x4221
TempC/T2,T1
0x4222
TempC/T2,T1 relative
0x4231
TempC/T1-T2
0x4241
TempC/T2-T1
0x4311
TempF/T1,T2
0x4312
TempF/T1,T2 relative
0x4321
TempF/T2,T1
0x4322
TempF/T2,T1 relative
0x4331
TempF/T1-T2
0x4341
TempF/T2-T1
0x5111
Resistance
0x5112
Resistance relative
0x5211
Beeper/Short
0x5212
Beeper/Open
0x5311
Admittance
0x5312
Admittance relative
0x6111
Diode/Normal
0x6112
Diode/Alarm
0x6211
Capacitance
0x6212
Capacitance realative
0x7111
Frequency
0x7112
Frequency relative
0x7211
Duty cycle
0x7212
Duty cycle relative
0x7311
Pulse width
0x7312
Pulse width relative
0x8111
uADC/normal
0x8112
uADC/normal relative
0x8121
uADC/AC+DC
0x8122
uADC/AC+DC relative
0x8131
uADC/peak
0x8211
uAAC/normal
0x8212
uAAC/normal relative
0x8221
uAAC/Hz
0x8231
uAAC/peak
0x9111
mADC/normal
0x9112
mADC/normal relative
0x9121
mADC/AC+DC
0x9122
mADC/AC+DC relative
0x9131
mADC/peak
0x9211
mAAC/normal
0x9212
mAAC/normal relative
0x9221
mAAC/Hz
0x9231
mAAC/peak
0xA111
ADC/normal
0xA112
ADC/normal relative
0xA121
ADC/AC+DC
0xA122
ADC/AC+DC relative
0xA131
ADC/peak
0xA211
AAC/normal
0xA212
AAC/normal relative
0xA221
AAC/Hz
0xA231
AAC/peak
value
description
0x00
Auto range
0x01
60 mV/6 V/600 uA/60 mA/600 Ohm/60 Hz/6 nF
0x02
600 mV/60 V/6000 uA/600 mA/6 KOhm/600 Hz/60 nF
0x03
600V/60 KOhm/6 KHz/600 nF
0x04
1000 V/600 KOhm/60 KHz/6 uF
0x05
6 MOhm/600 KHz/60 uF
0x06
60 MOhm/6 MHz/600 uF
0x07
60 MHz/6 mF
0x08
60 mF
bit(s)
description
0
Positive overload (0: no, 1: overload).
1
Negative overload (0: no, 1: overload).
4..7
A number of digits after decimal point.
Positive and negative overloads aren't mutually exclusive and can be simultaneously.
offset
size
description
5
4
Main value (float32).
9
1
Main value's precision byte (see above).
10
8
0-terminated string consists a unit of measurement.
18
4
Aux1 value (float32).
It's optional (check bit 1 of misc byte).
22
1
Aux1's precision byte (see above).
It's optional (check bit 1 of misc byte).
23
8
0-terminated string consists a unit of measurement.
It's optional (check bit 1 of misc byte).
31
4
Aux2 value (float32).
It's optional (check bit 2 of misc byte).
35
1
Aux2's precision byte (see above).
It's optional (check bit 2 of misc byte).
36
8
0-terminated string consists a unit of measurement.
It's optional (check bit 2 of misc byte).
44
4
A bargraph value (float32).
It's optional (check bit 3 of misc byte).
48
8
0-terminated string consists a unit of measurement.
It's optional (check bit 3 of misc byte).
If the packet doesn't consist aux1 or aux2 values all offsets starting 18
should be shifted.
offset
size
description
5
4
Relative value (float32).
9
1
Relative value's precision byte (see above).
10
8
0-terminated string consists a unit of measurement.
18
4
Reference value (float32).
22
1
Reference value's precision byte (see above).
23
8
0-terminated string consists a unit of measurement.
31
4
Absolute value (float32).
35
1
Absolute value's precision byte (see above).
36
8
0-terminated string consists a unit of measurement.
offset
size
description
5
4
Current value (float32).
9
1
Current value's precision byte (see above).
10
4
Max value (float32).
14
1
Max value's precision byte (see above).
15
4
A number (unsigned integer) of seconds since start of the measurement until a moment when the max value has been updated.
19
4
Average value (float32).
23
1
Average value's precision byte (see above).
24
4
A number (unsigned integer) of seconds since start of the measurement until a moment when the average value has been updated.
28
4
Min value (float32).
32
1
Min value's precision byte (see above).
33
4
A number (unsigned integer) of seconds since start of the measurement until a moment when the min value has been updated.
37
8
0-terminated string consists a unit of measurement.
offset
size
description
5
4
Max value (float32).
9
1
Max value's precision byte (see above).
10
8
0-terminated string consists a unit of measurement.
18
4
Min value (float32).
22
1
Min value's precision byte (see above).
23
8
0-terminated string consists a unit of measurement.
offset
size
description
0
4
Date/time (see below).
5
N
Measurement packet.
bit(s)
description
0..5
Year - 2000
6..9
Month
10..14
Day
15..19
Hour
20..25
Minute
26..31
Second
offset
size
description
0
11
0-terminated string, name of record.
11
8
0-terminated string, unit of measurements.
19
2
sampling interval in seconds.
21
4
duration of record in seconds.
25
4
a number of samples.
29
4
max value (float32).
33
1
max value's precision byte.
34
4
average value (float32).
38
1
average value's precision byte.
39
4
min value (float32).
43
1
min value's precision byte.
44
4
record beginning date/time (see 'Date/time format').
offset
size
description
0
1
a number of samples in the packet (N).
i*9 + 0
4
sample value (float32).
i*9 + 4
1
precision byte.
i*9 + 5
4
sample data/time (see 'Date/time format').
i is 0..N-1.
offset
size
description
0
1
0x01
1
2
mode (uint16, see above)
offset
size
description
0
1
0x02
1
1
range (uint8, see above)
offset
size
description
0
1
0x03
1
4
value (float32)
offset
size
description
0
1
0x04
1
4
0x01
offset
size
description
0
1
0x04
1
4
0x00
offset
size
description
0
1
0x05
1
1
0x01
offset
size
description
0
1
0x05
1
1
0x00
offset
size
description
0
1
0x06
offset
size
description
0
1
0x07
1
2
index (uint16)
Get saved measurements count
offset
size
description
0
1
0x08
offset
size
description
0
1
0x09
1
2
index (uint16)
If index == 0xFFFF it'll delete all saved measurements.
offset
size
description
0
1
0x0A
1
11
name (0-terminated string)
12
2
interval (uint16)
14
4
duration (uint32)
name can contains ASCII only.interval and duration unit is a second.
offset
size
description
0
1
0x0B
offset
size
description
0
1
0x0C
1
2
index (uint16)
offset
size
description
0
1
0x0D
1
2
index (uint16)
3
4
samples offset (uint32)
offset
size
description
0
1
0x0E
offset
size
description
0
2
0x5A12