Peter thank you very much for your prompt answer. I'm just a chemist playing with computers and have no experience with hexadecimal (if you can suggest me a internet site for dummy's  I would appreciate). when I tried to change the address it request for only two characters, so what should I type to get the result you mention in your note (0x01h)

Regards

Sorry for the silly question, but I'm stoked on the communication, and I thought that probably it should be the problem

-I verified the Com port . I enable/disable RTS,DTR and the screen turn on/off accordingly
-Other settings

EOFEnable: off
Handshaking: 0 (none)
Inputlen 0
InputMode 0 (text)
RThreshold: 1
Settings: 9600,n,8,1

I tested using Hyperterminal but neither have answer with the command #010

I have the "Description of communication protocols" document

It is not the problem, it is property. See device manual page 8. Manual is available at http://www.cometsystem.cz/english/manua … 3_4_10.pdf

Jumper
Jumper is located next to connection terminals. If communication protocol compatible with
standard Advantech-ADAM is selected, its function is the following:
· If jumper during switching ON the power is closed, device always communicates with
following parameters regardless stored setting in the device:
communication speed 9600 Bd, without check sum, device address 00h
· If jumper during switching ON the power is not closed, device communicates in accordance
with stored setting.
· If jumper is closed during device operation, device temporarily changes its address to 00h, it
will communicate in the same communication speed as before closing jumper and will
communicate without check sum. After jumper is opened setting of address and check sum
is reset in accordance with values stored in the device.