UNI-T UT71x series
Revision as of 15:46, 25 October 2014 by Uwe Hermann (talk | contribs) (Created page with "{{Infobox multimeter | image = 180px | name = UNI-T UT71x | status = in progress | source_code_dir = | counts...")
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| Status | in progress |
|---|---|
| Counts | 20000/40000 |
| IEC 61010-1 | CAT III (1000V) / CAT IV (600V) |
| Connectivity | RS232 / USB |
| Measurements | voltage, resistance, diode, continuity, capacitance, frequency, duty cycle, current, temperature, power (only UT71E), loop current (not on UT71B) |
| Features | autorange, hold, peak hold, relative, min/max, bargraph, backlight, true-rms |
| Website | uni-trend.com |
The UNI-T UT71x is a series of 20000/40000 counts, CAT III (1000V) / CAT IV (600V) handheld digital multimeters with RS232 or USB connectivity.
Devices
| Device | Conrad OEM | Tenma OEM | Counts | Comments |
|---|---|---|---|---|
| UNI-T UT71A | Voltcraft VC-920 | 20000 | ||
| UNI-T UT71B | Tenma 72-7730 | 20000 | ||
| UNI-T UT71C | 40000 | |||
| UNI-T UT71D | Voltcraft VC-960 (?) | Tenma 72-7732 | 40000 | |
| UNI-T UT71E | Voltcraft VC-940 | Tenma 72-9380A | 40000 |
Protocol
The devices use a simple 11-byte protocol over a USB-to-serial or USBHID-to-serial link (depending on the cable used).
The communication parameters are 2400 baud, 7o1. However, the vendor software opens the serial port with 8n1 settings, so the vendor protocol descriptions are slightly off. Also, the available vendor protocol descriptions from e.g. Conrad are partially incomplete or even erroneous in some places.
| Byte | Description | Comments |
|---|---|---|
| 0 | Digit 1 | |
| 1 | Digit 2 | |
| 2 | Digit 3 | |
| 3 | Digit 4 | |
| 4 | Digit 5 | |
| 5 | Range | |
| 6 | Function | |
| 7 | State 1 | |
| 8 | State 2 | |
| 9 | \r (0x0d) | |
| 10 | \n (0x0a) |
The following information is not available/sent via the protocol (and is thus unavailable for sigrok purposes):
- the REL, MIN, MAX, HOLD flags
- the bargraph value
- the backlight status
- the low-battery indicator
- the internal measurement value store (only available on some models)