Quantum Composers Motorized Attenuator - Manual (Page 5)

6 Command Set
The motorized attenuator communicates via a standard RS232 connection. The default
communication settings are 57,600 baud, 8 data bits, even parity and 1 stop bit (57600,
8, E, 1). A typical serial port pin out is shown below. Only the Rx, Tx and Gnd are used
to communicate with the aperture. The included software can be used to operate the
unit over the serial port at the default baud rate of 57,600.
Typical PC Serial Port (DB9)
Pin No. Name Description
1 DCD Data Carrier Detect †
2 Rx RS232 Receive
3 Tx RS232 Transmit
4 DTR Data Terminal Ready †
5 Gnd Ground
6 DSR Data Set Ready †
7 RTS Request to Send †
8 CTS Clear to Send †
9 RI Ring Indicator †
† denotes signal not used by the module
Device Command Format
All commands use ASCII characters and are composed of the following fields:
<Prefix><Address><Deliminator><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.
Deliminator 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.