SimStep
Manual - 3400 Iss. D
7
th
June 2004
page 25
8.4 General Command Structure
The PM600 responds to a character string (sent over the RS232 interface) that
defines a command in the following way:
adXXnnn<cr>
where
ad
=
address
for the axis (see 8.1 above)
XX
=
command notation
– all commands are two letters
nnn
=
numeric value
for the command argument (if required)
<cr>
=
carriage return
Command strings must be terminated with a carriage return (ASCII 0D hex). Upper or
lower case characters maybe used for the command. Spaces in the command line are
ignored. Commands are acted upon sequentially, as they have been entered.
8.5 Examples of Command Structure
Set-up commands:
2SA5000
Set Axis 2 acceleration to 5000 steps/sec
2
1LL-20000
Set Axis 1 lower software limit to –20000 steps
1QA
Query all settings for Axis 1
M
OVE COMMANDS
:
1MR5000
Move Axis 1 relative to current position by +5000 steps
1ST
Soft stop on Axis 1
2MA-2000
Move Axis 2 to absolute position –2000 steps
2OA
Output the encoder position of Axis 2
The
SimStep
controller responds to all commands once the command has been
accepted. However, not all commands can be accepted immediately. For example, a
move command sent whilst a previous command is still taking place, will be delayed
until the previous one is finished. Commands in general will have an OK response.
Some commands, however, will produce a numeric response (e.g.2OA) or produce a
string of data (e.g. 1QA).
All replies are preceded by the address of the axis that generated the response – e.g.
for axis one the replies will be preceded by
01:OK
.
Important
– if the set-up of the PM600 is changed then the
BA
(backup all command)
must
be executed to save set-up values and sequences to Flash memory. If this not
done, the values will be lost on power-down.
The user may encounter error message from the controller under certain
circumstances, e.g. mistakes in commands or conflicting instructions. The messages
are usually self-explanatory; they are listed on page 8-1 of the PM600 manual.
