TestController and Brymen BM869s

[a_uli]

Hi!
I try to connect a BM869s to HKJ's TestController (thank you for this very promising logging systrem!) on a Linux system. The Brymen BM869s socket doesn't work under Linux, as I was told by HKJ. So I try to use the alternative BM869s (serial) socket. Currently I test on a Win10-64 computer.

As serial interface I copied the device presented by jesuscf - also thanks for sharing this design.  I use his ino-file on an old MEGA 2560. Connection is via a virual com port. The baud rate is 115200.

The serial interface works fine with hterm. The commands "*IDN?", "MEAS?", MEAS1?", "MEAS2"  yield the expected results.
In TestController (in debug mode)  I selected the BM869s (serial) socket. I enter  commands in the "BM869"-line of TestController's Commands tab.  The protocol appears in the cmd window opened by testControllerDebug.bat:

Starting
;; jSerialComm version: 2.10.3
;; Start thread for: COM13 - Brymen BM869s (Serial)
;; COM13: Set params: 115200
;; Found Brymen BM869s (Serial) on Arduino Mega 2560 (COM13) (COM13)
*IDN?
;; BM869: Tx <*IDN?>
;; BM869: Rx <Brymen,Brymen BM869s,>
;; Brymen,Brymen BM869s,
MEAS1?
;; BM869: Tx <MEAS1?>
;; BM869: Rx Timeout

I assume nothing is sent via USB, although  "*IDN?"  seems to give  a result. But this is fake, because I changed the return string in the Arduino firmware to some absurd value. This value is not returned - or it is replaced by TestController with " Brymen,Brymen BM869s" ()
And the "MEAS?" commands do not trigger a read on the IR interface. With hterm they do (observed with a scope).

What is wrong with my setup? Any hint is welcome.

Uli