Durand Interstellar, Inc. Switch-4 User manual

Switch-4
MIDI and RS-232 Versions
PC Board Revision 1
January 14 2011
Instruction Manual
Durand Interstellar, Inc.
219 Oak Wood Way
Los Gatos, California 95032 2523
www.interstellar.com
tel: [phone], USA toll free: 1 866 356 3886

Table of Contents
Table of Contents.................................................................................................................i
Intended Use.......................................................................................................................1
Specifications......................................................................................................................2
Mounting.............................................................................................................................3
Wire Connections................................................................................................................4
Testing.................................................................................................................................6
Standard Commands...........................................................................................................
Customizing the Switch-4...................................................................................................8
California Proposition 65 Warning.....................................................................................9
Warranty............................................................................................................................10

Intended Use
The Switch 4 interface will allow up to four switch inputs to send commands to a
host device (such as a PC running ShowMan, a Mac running QLab a lighting
control board, a PLC, or other musical or digital equipment). The Switch 4 is
offered in MIDI and RS 232 versions with customization available.
Since the data sent by the Switch-4 has no error checking it should not be
used to control anything that might be damaged or cause injury if the
wrong data is received.
The Switch 4 is designed to be continuously powered, typical power use is about
1/10th of a Watt so it meets all energy conservation requirements.
This device complies with part 15 of the FCC Rules. Operation is subject to the
following two conditions: (1) This device may not cause harmful interference, and
(2) this device must accept any interference received, including interference that
may cause undesired operation.
The only user serviceable parts inside are the screw terminals. Re attach the
cover securely being careful to not bend the LED. Never apply power with the
cover removed.
The latest version of this manual, and any application notes are available from
our support site:
http://interstellar.com/support.html
All of our documentation is in Adobe Acrobat format. Download a free reader
from:
http://www.adobe.com
All trademarks are the property of their owners and are used for reference only.

Specifications
•Width: 3.5” (89mm) including mounting flanges
•Height: 2.5” (64mm)
•Thickness: 1” (25mm)
•Mounting: Two 0.19” (4.8mm) diameter holes on 3” (76.2mm) centers.
•Weight: 2oz (60gm)
•Connections: Screw terminals
•Power supply: 9 24VDC, 50mA max (shorted output cable), normal draw
is about 10mA (varies slightly with model)
•Environmental: 32 100° F (0 40° C), non condensing humidity
•Switch inputs: Four contact closure or logic level. Active LOW with internal
pullup resistors.
•Debounce: 20mS on both Open and Close.
•Initial Delay: Switches are ignored for about 5 seconds after power up.
•Data output: MIDI Note commands, RS 232 characters, or customized.
•Output Levels: 0V and 5V, current limited.
Note: The RS-232 specification calls for voltage levels of -12V to -3V for
“Mark” but except in very rare cases RS-232 receiver chips allow a “Mark”
to be as high as +0.8V. The Switch-4 uses 0V for “Mark” and should have
no problem working with all modern devices. If you have any concerns you
may contact us for help in verifying the levels needed for your application.
MIDI operation is fully compliant with the specification and recommended
practices.

Mounting
The Switch 4 is designed to be mounted to a wall or inside another enclosure
such as a kiosk. It is intended for indoor use but may be used outdoors if
protected from moisture and excessive heat/cold.
When mounted to a vertical surface, the screw terminals (J1 in the illustration
below) should be on the bottom. This lets the wires hang freely and also
prevents any foreign material from falling in through the slot in the box.
J2 is only used for initializing the Switch 4 during manufacture, it is not used in
normal operation except in some custom applications.
Be sure to allow room to remove the cover in case you need to remove or add a
wire in the future. Support the wires to the mounting surface as needed.

Wire Connections
If possible, connect all the wires before mounting the Switch 4, this will make it
easier to get the wires into the screw terminals. Remove the cover being careful
to not bend the LED. Refer to the illustration above when connecting wires.
•Make sure to not leave any loose pieces of wire or other foreign material
inside the Switch 4, a short could destroy the device.
•Your DC power supply should have two wires, a positive and a negative or
ground. Connect the positive wire to the terminal marked “9 24VDC” and
the negative wire to the terminal marked “GND”. The Switch 4 is protected
from reverse polarity, so if you're not sure which wire is which you may
apply power at this point. If the LED doesn't come on within a couple of
seconds, turn off the power and reverse the wires.
•With the power off, continue making connections.
•The switch inputs are pulled up to 5VDC with 10KΩ resistors. If you are
using buttons, they will often be normally open (NO) momentary push
buttons. If using other types of switches, you only need single pole single
throw (SPST) but almost any type can be used by leaving unused
connections open. Very large switches intended for high current may be
electrically noisy and may need a capacitor across them to prevent
multiple detections. Contact us if you need any help with switches.
•If using solid state devices (light beam sensors, motion sensors, etc.) you
may use ones with contact closures, open drain or open collector
transistor outputs, or logic levels (3V to 5V levels will work). Other types of
solid state devices may need a resistor added, please contact us for
assistance.
•Switch #1 connects between the terminal marked “SW1” and either the
terminal marked “COM” or the “GND” terminal (power supply ground).
•Switches 2 4 connect in the same fashion. Any unused inputs should be
left open (no connection).
MIDI Connections
•Your MIDI cable should have two or more insulated wires and a bare
shield wire which may also connect to pin #2 of the MIDI plug.
•Connect the SHIELD wire (and the pin #2 wire, if there is one) to the
terminal marked “SHIELD”.
•The “D+” terminal connects to pin #4 of the MIDI plug.
•The “D ” terminal connects to pin #5 of the MIDI plug.
RS-232 Connections
•RS 232 cables have two different pinouts called DCE and DTE. You must
determine the proper pinout for the equipment you are using.
•Connect the GROUND pin (typically pin 5 of a 9 pin connector) to the
SHIELD terminal.
•Connect the RX pin (typically pin 2 of a 9 pin connector intended to plug

into a PC) to the “D ” terminal. RX refers to your equipment, it's the pin
your equipment expects to receive data on.
•If you have any other pins (possibilities are DCD, DTR, DSR, RTS, CTS,
RI) that need to be held at “Space” for your application, connect them to
the “D+” terminal.
•All unused pins should be left open, tape wire ends to prevent shorts.

Testing
Check that there are no pieces of wire or other foreign material inside the
enclosure and then replace the cover. Be careful to not bend the LED, it is
supposed to fit into a hole in the lid.
Turn on the DC power and note that the Status LED comes on in about 1
second. You may also turn on whatever device is receiving the MIDI data.
Wait 5 seconds or more for the Initial Delay to complete. This delay is to let your
system stabilize after power up with no false commands. During this time any
switch changes are ignored and no commands will be sent.
Now one at a time operate each switch, note that the Status LED blinks off once
for each time any switch changes state (once for opening and once for closing).
If you see multiple blinks instead of just one, it means your switch is bouncing
longer than the debounce time (20mS). This is often caused by a dirty or noisy
switch, cleaning the contacts may very well fix this. If you can't clean the switch
or it is a type that has a very noisy contact, adding a small capacitor in parallel
with the switch (between the SW screw terminal and COM or GND) will normally
solve this. The capacitor value isn't critical, something around 1μF should work
fine.
If you haven't already, turn on the device that is to receive the data and verify
that you are receiving the appropriate commands.

Standard Commands
If you have a custom Switch-4, see the additional documentation that came
with it for the commands it sends.
MIDI Commands
All MIDI commands are sent on channel 1 (it may be called channel zero on your
system).
The MIDI commands sent are:
•Switch #1 ON sends “Note 1 On Velocity 64” (0x90 0x01 0x40)
•Switch #1 OFF sends “Note 1 Off Velocity 64” (0x80 0x01 0x40)
•Switch #2 ON sends “Note 2 On Velocity 64” (0x90 0x02 0x40)
•Switch #2 OFF sends “Note 2 Off Velocity 64” (0x80 0x02 0x40)
•Switch #3 ON sends “Note 3 On Velocity 64” (0x90 0x03 0x40)
•Switch #3 OFF sends “Note 3 Off Velocity 64” (0x80 0x03 0x40)
•Switch #4 ON sends “Note 4 On Velocity 64” (0x90 0x04 0x40)
•Switch #4 OFF sends “Note 4 Off Velocity 64” (0x80 0x04 0x40)
RS-232 Commands
All RS 232 commands are sent at 9600 bits per second (baud), 8 data bits, no
parity, and timed so they will work with 1, 1½, or 2 stop bits.
The RS 232 commands sent are:
•Switch #1 ON sends “A\r” (capitol 'A' followed by a carriage return)
•Switch #1 OFF sends “a\r” (lower case 'a' followed by a carriage return)
•Switch #2 ON sends “B\r”
•Switch #2 OFF sends “b\r”
•Switch #3 ON sends “C\r”
•Switch #3 OFF sends “c\r”
•Switch #4 ON sends “D\r”
•Switch #4 OFF sends “d\r”

Customizing the Switch-4
You may order the Switch 4 customized in several ways, contact us for details.
Items that can be customized
•No enclosure or different enclosure
•Switches mounted on the enclosure
•MIDI or RS 232 output
•Baud rate for RS 232
•Debounce time (0 65mS in 4mS steps)
•Data sent for each switch action.
•For MIDI this may be any string of hex data, notes, controls, MIDI
Show Control, etc.
•For RS 232 this may be any string of 8 bit data except null (zero).
•Data strings may be reused, for example the same string can be
used for all Switch Off strings.
•The total space for all strings combined is 168 characters (text
characters or MIDI bytes). If all strings are the same length that's
21 characters per string.
•Any strings may be null (nothing sent).
•For a small additional fee you can have an extended version of the
Switch 4 with about 1,400 characters of storage. Check with us for
the latest options.
•Other customization possibilities exist such as precision delays and other
timer functions, counters (resettable or non resettable), different actions
depending on how long a switch is held, and others. We can also supply
full custom units with many more inputs, other outputs, whatever you may
need.