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distinguished by using the notation 0xXXXX, 0xYYYY etc.
ASCII Commands and Replies (RS-232)
Command and Reply Structure
RS-232 commands and replies are structured as follows:
Every command sent from the master must be preceded by a ”dollar” character
($).
Every command sent from the master must be terminated by a ”greater than”
character (>). This terminating character will be referred to as the prompter in the
rest of this document.
There will be no output from the SLS sensor until the prompter has been received.
Between the leading ”dollar” character and the prompter comes the actual
command. It consists of a command character (always an uppercase letter) and
possibly a numerical parameter, depending on the command. The commands
belonging to the batch class described in section Batch Commands may be
concatenated in a single command, so that there may be up to four command
characters at the same time.
The SLS sensor outputs a prompter as soon as it is ready to process commands
after power on. No commands may be issued by the master until it has received
this initial prompter.
Replies from the SLS sensor always start with the command character and end
with the prompter. In between there may be data, depending on the command.
There is no initial ”dollar” character in the reply.
The master may not output a new command until it has received a prompter back
from the SLS sensor in response to the previous command.
Illegal commands, commands whose parameters are outside the legal range, and
commands which contain more characters than the maximum (12 characters) will
be rejected by the SLS sensor.
Batch Commands
The ”Distance Value”, ”Measurement Validity”, ”Laser Intensity” and ”Probe
Temperature” commands all take a parameter nnnnn, which determines how
many values the SLS sensor should transmit. The data transmitted as a result of
such a command is referred to as a batch in the rest of this document. These four
commands may also be concatenated into a single command. In this case they
may appear in any order, but they must precede the nnnnn parameter. The
parameter applies equally to all the data types in the command (i.e. it is not
possible to ask for one number of distance values and another number of
temperature values).
Non-Volatile Memory
All software parameters are stored in a Flash memory inside the sensor.
Parameters can be changed by serial commands (RS-232 as well as RS-422), but
they cannot be stored in the Flash memory when changed in that way. The only
way to make new parameter values permanent is to use the sensor's interactive
setup menu (see section "Parameter Setup" later in this appendix).
The reason for this behavior is that it takes a long time – several seconds – to
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