Page 16 of 32
Rev 0.95
Serial RS232 interface
To be described
Remote control commands
There are two sets of commands for controlling the MPS, SCPI commands and a subset of the
commands used for the older models of the Danfysik MPS.
4.3.1.
SCPI commands
The SCPI communication protocol is based on the IEEE standard “
Standard Commands for
Programmable Instruments
” (SCPI) but only a subset of commands
is implemented. The
definition of the standard can be found here:
http://www.ivifoundation.org/docs/scpi-99.pdf
However, this is rather lengthy and an easier to read example of how it can be implemented
can be found here:
http://www.us.tdk-lambda.com/hp/pdfs/product_manuals/83034100.pdf
, please see
page 35-45.
In short, SCPI is a standard set of commands implemented by many of the major instrument
companies, making it much easier to implement different instruments in software.
Most SCPI commands, but not all, have “set” version and an “ask” version. Example:
•
The command “OUTP:CURR 22.56” sets the current to 22.56 amps.
•
The command “OUTP:CURR?” asks for the current set value and will return “22.56”.
The computer uses port 13000 for the SCPI communication.
The implemented commands are listed in Table 1.
Table 1: Implemented SCPI commands
Command
Description
*CLS
Clear status command, same as the reset
command *RST
*IDN?
Identification query. The response includes the
PLC version as well as the parser version.
*RST
Reset command, resets all interlocks.
*STB?
Returns the Status register. The command is
equivalent to STATus?
SYSTem:ERRor[:NEXT]?
Returns the top entry of the status queue for the
parsing of the commands in the format "error#,
error text". Error# 0 means no error. When the
command is issued the entry is removed from the
queue and next entry is brought to the top of the
queue.
SYSTem:VERSion?
Returns the software release number
