Serial read/write in batch file?

[4lex]

Hello all. I'm trying to write a request to COM2 and capture the answer. My device is 19200 baud 8/1 non parity.

Using a freeware terminal called termite I can send the hex instruction and receive the answer, as verified in HHD serial monitor.

My batch file looks like this:

MODE COM2: baud=19200 parity=N data=8 stop=1 to=off
TYPE request.txt>COM2
COPY COM2 text.txt

where request.txt contains my request.

HHD sees the request being written, but the device does not respond.

Any ideas please?

Cheers,
Alex

 

[bigmck]

Are you aware this is a Windows 7 forum?

 

[4lex]

No shit sherlock. This behaviour differs from XP.

 

[UsernameIssues]

Try sending the file via teraterm pro

Download Tera Term 4.75 :: Freeware | Download

 

[richnrockville]

Hello all. I'm trying to write a request to COM2 and capture the answer. My device is 19200 baud 8/1 non parity.

Using a freeware terminal called termite I can send the hex instruction and receive the answer, as verified in HHD serial monitor.

My batch file looks like this:

MODE COM2: baud=19200 parity=N data=8 stop=1 to=off
TYPE request.txt>COM2
COPY COM2 text.txt

where request.txt contains my request.

HHD sees the request being written, but the device does not respond.

Any ideas please?

Cheers,
Alex

Can it be assumed that your sending an AT command string. The copy com2
I believe should be com2: but I am not 100% sure. It can get tricky sending a command too fast and then missing the response which normally is pretty fast.

Can you send the commands from the terminal window and see what the response is at that point?

Rich

 

[4lex]

Thanks both. I can successfully capture the traffic if i send the commands using a terminal.

I'm not sending an AT string, the device in question is an inverter, I'm querying various registers for performance and environmental stats using a proprietory protocol. The weird thing is I can seee the write being sent from the batch file, which in hex appears identical to the request I send from the terminal program (using HHD serial monitor), but the device doesn't respond - though it does in a winxp environment.

I wanted to use a batch file environment so I can call this from another program, I'm looking for a 1hz sampling resolution.

Cheers,
Alex

 

[richnrockville]

Alex, are you sending the device a cr/lf at the end of the data line? I would send a eof (cntrl+Z) or F6

If so, that might be masking the reply..

Rich

 

[4lex]

No, nothing like that. What I did was write the ascii characters of this string:
0x02 0x05 0x01 0x02 0x10 0x02 0xE0 0x3D 0x03
into request.txt, I'm now wondering if I have somehow made a mess of that by opening it in a text editor.

Will have another go.

Cheers,
Alex

 

[4lex]

And the quick answer is it would appear not
Reviewing the file with HXD hex editor I see only this
02 05 01 02 10 02 E0 3D 03
Hmm.

 

[richnrockville]

4lex, I don't see a control+Z at the end of the hex string. But then your editor could be stopping
at that point.

are you doing a copy /b
of the file

Rich

 

[4lex]

Thanks Rich. I'm not sending an EOF as the data I'm sending isn't a file per se, the protocol is defined such that the requests are bound by 0x02 [Start] and 0x03 [End].

It's not as if the batch file is getting stuck writing to COM, it does complete with a "1 file(s) copied" echo, but the output file is zero length.

Thanks for the pointer on the /B flag, I didn't know about that. I will see where that takes me, cheers.

Alex