MINISYSTEM Manual Version 1.5
Page 24
7.
USB Communications
Personal Computer to Laser System Communication
The MINISYSTEM has a standard USB port. All menu settings can be set and retrieved over the
computer interface using a simple command language. The command set is structured to be
consistent with the Standard Commands for Programmable Instruments (SCPI). Although due to the
high number of special features found in the miniSystem, many of the commands are not included in
the specification. Sending commands faster than 50 ms may cause the unit to not respond
properly. It is advised to wait until a response from the previous command is received before
sending the next command.
USB Interface Overview
The USB port is located on the bottom of the MINISYSTEM laser payload and uses a USB-B
type connector with the following pinout (as viewed from the back of the unit):
Pin Number
Name
Description
1
+5 VDC
Vbus
2
D-
Data -
3
D+
Data +
4
Ground
Power Return
Device Command Format
All commands use ASCII characters and are composed of the following fields:
<Prefix><Address>< Delimiter ><Command String>[Parameters]<Terminator>
Field
Description
Prefix
Single semicolon character ";", must precede all commands. All
devices will reset their command input buffer when the prefix is
received.
Address
2 ASCII characters. Each device has a unique address which is
programmed into its firmware. See the table below for a list of
addresses.
Delimiter
Single colon character “:”, must follow device address.
Command
String
Commands are specific to each device -- see the following
sections for the commands that each device supports.
Parameters
(optional field) Some commands may not require a parameter.
For Query commands immediately follow the command string with
the questi
on mark character ”?”. For non-query commands
immediately follow the command string with a single space
character ” “ followed by the parameter. Multiple commands are
separated by commas.
Terminator
ASCII carriage return character (ODh). The receiving device does
not process any commands until the terminator is received.
