GW instek LCR-819 meter no-RS232 problem

[Serg32]

Hi,

I've got GW instek LCR 819 meter in good conditions and its quite good for me. But there is a problem it got no COM (RS232) port to connect to PC.
There is a 4 screw metal cover on the back of the device and there is a 26 pin connector on the main board of the device to connect RS232 option cover. The meter is very old and there is no way to buy this RS232 option cover separately.

So, the Q:
1. It is possible to connect to this 26 pin connector and use it for communication between meter and PC using some digital I/O USB box/board?
2. Is there any documentation considering this 26 pin connection port about protocol, pin-out, timing diagram and so on? May be it uses some continuous "frame" transfers with WORD or DWORD?
For instance, in the GW instek LCR 826 meter (another from that 800 series) there is a 25 pin connector on the rear metal cover for Handle interface to work with some sorting system. It uses some digital I/O with appropriate timing diagram for communication.

[KungFuJosh]

https://www.gwinstek.com/en-global/products/downloadSeriesDownNew/13514/766
Opt.01     RS-232C Interface ( Factory Installed )

It appears they may not have sold it as an accessory separately, but you might be able to find the option card or more info on it to answer your question about the interface.

Interesting also is Opt.02 which maybe was sold separately? See photos: https://www.ebay.com/itm/395645276673