RS232 comm problem under Win 10 (Burster Kelvimat 4323)

[Juergen_R]

Hi everyone,

I was forced to upgrade some Win7 machines to Win10. Since then, the Burster Kelvimat 4323 has communication issues (same exe, LV2018 SP1 32bit, NI-Serial 17.5.0)

Error after PC restart:

• Device doesn't respond to *IDN? query
• response to next command (e.g. read Channel A0) is the IDN string
• every successive command has a "delay" of 1 message
• reinitialization doesn't change this behaviour (next *IDN? query gets response of last measurement and so on)

Some additional information:

• the delay can grow (I saw delays of up to 3 messages, I don't know when/ how this happens)
• the error can rarely appear even after an successful initialization (which makes this way worse...)
• restarting the Burster solves the error. Restarting the PC makes the error appear.
• the Burster doesn't support any restart / reset / initialize / ... command
• RTS/CTS handshake is used, I/O config is RS232 9600,8,0,1,1
• you probably won't find a manual for it, but I have a hardcopy if you have specific questions
• COM driver is Serial.sys V10.0.17763.1
• I have attached logs of both an successful init and a failed one

(some of the) things I tried so far:

• changed device and PC
• used an older COM driver
• changed timing and added delays 
• used different / additional termination chars
• contacted support (since the device is quite old the manufacturer and the provider point to each other for help and none can provide it...)

If you have any ideas whats wrong or how to narrow down the problem let me know!

Thanks for reading

Jürgen