V&A VA40B

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VA40B
VA40B front.JPG
Status
Counts 6000
IEC 61010-1 CAT III (1000V) / CAT IV (600V)
Connectivity USB
Measurements voltage, current, resistance, capacitance, frequency, temperature, duty cycle, diode, continuity
Features autorange, data hold, relative, min/max, backlight

The VA40B is a 6000 count CAT III (1000V) / CAT IV (600V) handheld digital multimeter with USB connectivity.

Hardware

Multimeter:

  • TODO

USB cable:

  • Prolific USB-to-Serial Comm Port
  • TODO

Photos

Protocol

14-byte LCD segments over USB-2-serial (Prolific chip, 2400 baud, 8n1).

The DMM IC used in this multimeter is probably a Fortune Semiconductor FS9721_LP3 or alike, see Multimeter_ICs#Fortune_Semiconductor_FS9721_LP3 for the protocol.

The manufacturer specific last byte of the 1 byte packet (numbered 0xe) is as follows:

Byte Bits 7-4 Bit 3 Bit 2 Bit 1 Bit 0
13 0xe MIN (unused?) °C MAX

To enable output to the PC on the multimeter you have to keep the Hz/DUTY key pressed while powering on the device. However, it will auto-poweroff (after roughly 1 hour?), even in this mode. To avoid that, press both the Hz/DUTY and the SELECT key during power-up (see manual page 19).

Resources