GW Instek GDM-397
 | |
| Status | in progress |
|---|---|
| Source code | serial-dmm |
| Counts | 4000 |
| IEC 61010-1 | CAT III (1000V) / CAT IV (600V) |
| Connectivity | RS232 |
| Measurements | voltage, current, resistance, capacitance, frequency, temperature, duty cycle, diode, continuity |
| Features | autorange, true-rms, data hold, relative, backlight |
| Website | gwinstek.com |
The GW Instek GDM-397 is a 4000 count CAT III (1000V) / CAT IV (600V) handheld digital multimeter with RS232 connectivity.
It is similar to the UNI-T UT61B, but not the same device/PCB (this appears to have improvet input protection along with HRC fuses).
Hardware
Multimeter:
- Multimeter IC: Fortune Semiconductor FS9922-DMM3 (datasheet)
- Crystal: 4MHz (markings: "3.999")
- Fuses: 600mA H 1000V (6.35x31.8mm) and 10A H 1000V (10.3x38.1mm) (HRC fuses)
RS232 cable:
See Device cables#UNI-T_UT-D02.
USB cable:
Photos
Front
Protocol
See Multimeter_ICs#Fortune_Semiconductor_FS9922-DMM3 for the DMM IC protocol. Depending on the cable, additional transport-specific decoding is needed, though.
Serial data transmission must be enabled by a long press on the "REL" button.