Tipps Serial Device Settings To Switch Off Every Hidden Manipulation

Introduction

In the case of the Keithley 2000 Digital Voltmeter, we saw that a Windows device could easily communicate via the RS-232 Interface using SCPI commands. Linux systems on the other side, reacted to commands input but weren't able to read anything back. Fiddling around with the stty settings, M.Traxler, GSI found / tried / out exactly the same settings as used for the HadCon2 devices.

Solution

• Output settings:

  -opost

  do not post-process output

  -onlcr

  do not translate newline to carriage return-newline

• Local settings:

  -isig

  do not enable interrupt, quit, and suspend special characters

  -icanon

  do not enable erase, kill, werase, and rprnt special characters

  -iexten

  do not enable non-POSIX special characters

  -echo

  do not echo input characters

  -echoe

  do not echo erase characters as backspace-space-backspace

  -echok

  do not echo a newline after a kill character

  -echoctl

  do not echo control characters in hat notation ('^c')

  -echoke

  kill all line by obeying the echoctl and echok setting

  19200

  sets the speed to 19200 Bit/s

Summarizing the settings prevent any additional manipulation of input or output.

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-- PeterZumbruch - 2017-11-30