View source for GW Instek GDM-397

{{Infobox multimeter
| image           = [[File:Gdm-397_front.png|180px]]
| name            = GW Instek GDM-397
| status          = supported
| source_code_dir = serial-dmm
| counts          = 4000
| categories      = CAT III (1000V) / CAT IV (600V)
| connectivity    = [[Device_cables#UNI-T_UT-D02|RS232]] 
| measurements    = voltage, current, resistance, capacitance, frequency, temperature, duty cycle, diode, continuity
| features        = autorange, data hold, relative, backlight
| website         = [https://www.gwinstek.com/en-global/products/detail/GDM-400_GDM-300 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).

Press and hold the '''REL''' button to enable serial data transmission.

== Hardware ==

'''Multimeter''':
* '''Multimeter IC''': [[Multimeter_ICs#Fortune_Semiconductor_FS9922-DMM3|Fortune Semiconductor FS9922-DMM3]] ([http://www.ic-fortune.com/upload/Download/FS9922-DMM3-DS-10_EN.pdf datasheet])
* '''Crystal''': 4MHz (markings: "3.999")
* '''Fuses''': 600mA H 1000V (6.35x31.8mm) and 10A H 1000V (10.3x38.1mm) (HRC fuses)

'''RS232 cable''':

* Included (appears to be same as [[Device cables#UNI-T_UT-D02]]).


'''USB cable''':
* Optional (appears to be same as [[Device cables#UNI-T_UT-D04]]).

== Photos ==

<gallery>
File:Gdm-397_front.png|<small>Front</small>
File:Gdm-397_pcb.jpg|<small>PCB</small>
File:Gdm-397 rs232cable.jpg|<small>RS-232 Cable</small>
</gallery>

== 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.

== Resources ==

* [https://www.gwinstek.com/en-global/products/downloadSeriesDownNew/9914/718 Datasheet]
* [https://www.gwinstek.com/en-global/products/downloadSeriesDownNew/9890/718 Manual]


[[Category:Device]]
[[Category:Multimeter]]
[[Category:Supported]]