Spectral Products AB300 Series User manual

Spectral Products
AB300-Series
Automated Filter Wheels
User Manual
1049478
August 2006
2659-A Pan American Frwy., NE Albuquerque, NM 87107 Tel [phone] Fax [phone]
www.spectralproducts.com

1. Introduction
1.1 Mission Statement
Our mission is to provide our customers with reliable products, on time, and at a fair price. We are continually striving to
maintain the highest standards, by assuring defect-free products and by providing prompt and courteous customer service.
The staff at Spectral Products will be happy to answer any questions about our products and our services. For immediate
assistance, please contact the Spectral Products Group directly at [phone], by fax [phone], or by e-mail at
[email protected]
1.2 Warranty
This product is warranted to be free of defects in materials and workmanship for one year from date of purchase.
This manual and the software it describes are provided free of charge as a service to the customer. The software is intended
to be used as a tool for development and as an example of one possible method of code implementation. It is not intended
to be a “user application.”
Any software associated with this product is provided “as is” with no warranty, expressed or implied. While it is Spectral
Products’ intent to provide error-free development tools, no guarantee is made regarding either the accuracy or usefulness
of this material.
Failures or damages resulting from lack of operator attention to proper procedures, failure to follow operating instructions,
unauthorized modifications, and natural disasters are not covered under this warranty.
SpectralProducts reserves the right, without prior or further notice, to make changes to any of its products described or
referred to herein to improve reliability, function, or design.
Spectral Products accepts no liability for incidental or consequential damages arising from the use of this software.
Spectral Products does not recommend the use of its components or software products in life support applications wherein a
malfunction or failure of the product may directly threaten life or result in injury.
Spectral Products does not recommend that this product be used on the same power line as other equipment with high
current draw requirements.
1.3 Copyrights
Spectral Products maintains the copyright on this material, but grants the customer rights to use or to modify the software
described herein without obtaining Spectral Products permission and without the requirement to reference Spectral Products
as the source of the material.
Spectral Products
2659-A Pan American Frwy., NE Albuquerque, NM 87107 Tel [phone] Fax [phone]
www.spectralproducts.com

Spectral Products
2659-A Pan American Frwy., NE Albuquerque, NM 87107 Tel [phone] Fax [phone]
www.spectralproducts.com
Table of contents
1. DESCRIPTION.....................................................................................................- 3 -
1.1 General Description ................................................................................................................................. - 3 -
1.2 Detailed Operation Description .............................................................................................................. - 3 -
2. OPERATION ........................................................................................................- 3 -
2.1 Mounting................................................................................................................................................... - 3 -
2.2 Filter Installation ..................................................................................................................................... - 3 -
2.3 Connections .............................................................................................................................................. - 4 -
3. PROGRAMMING .................................................................................................- 5 -
3.1 Overview ................................................................................................................................................... - 5 -
3.2 Commands................................................................................................................................................ - 5 -
3.2.1 Baud ................................................................................................................................................. - 6 -
3.2.2 Echo.................................................................................................................................................. - 6 -
3.2.3 EEPROM Read................................................................................................................................. - 6 -
3.2.4 EEPROM Write................................................................................................................................ - 7 -
3.2.5 Go to New Filter Position................................................................................................................. - 7 -
3.2.6 Query Position.................................................................................................................................. - 7 -
3.2.7 Reset ................................................................................................................................................. - 8 -
3.2.8 Step Down ........................................................................................................................................ - 8 -
3.2.9 Step Up............................................................................................................................................. - 8 -
3.2.10 Zero .................................................................................................................................................. - 8 -
4. OPERATION HINTS ............................................................................................- 9 -
5. SPECIFICATIONS .............................................................................................- 10 -
5.1 Mechanical.............................................................................................................................................. - 10 -
5.1.1 AB301, 1 Inch Aperture, 6 Position ............................................................................................... - 10 -
AB302, 2 Inch Aperture, 5 Position.............................................................................................................. - 11 -
5.1.2 5.1.3 AB303, ½ Inch Aperture, 12 Position ................................................................................... - 12 -
5.2 Electrical ................................................................................................................................................. - 14 -
5.2.1 RS232 In......................................................................................................................................... - 14 -
Power ............................................................................................................................................................ - 14 -
5.2.3 Filter Wheel.................................................................................................................................... - 14 -
5.3 Cables................................................................................................................Error! Bookmark not defined.
5.3.1 Computer to filter wheel RS232..................................................................................................... - 15 -
5.3.2 Filter wheel assembly to filter wheel controller ............................................................................. - 15 -

Spectral Products
2659-A Pan American Frwy., NE Albuquerque, NM 87107 Tel [phone] Fax [phone]
www.spectralproducts.com
2. DESCRIPTION
2.1 General Description
The AB300-Series Automated Filter Wheels consist of a motor driven wheel, a computer based controller, a power supply,
and one cable.
Filter wheel control is provided via RS232 from a host computer to the AB300-Series controller.
2.2 Detailed Operation Description
The filter wheel assembly has a stepper motor and a position sensing device. The motor drives the filter wheel via a belt.
The position sensing device allows the filter wheel to determine a “home” position during a reset. This home position is
some number of steps ( the “offset”) away from the filter 1 position. After home is found, the wheel automatically moves
to the filter one position.
The relative position of filter 1 is determined by the Filter 1 Offset, stored in non-volatile memory. From the filter 1
position, all other positions are reached by a fixed number of steps and are not individually programmable. If fine tuning of
each position is desired, the Step Up and Step Down commands may be used. This fine adjusting will not be saved
however, and subsequent moves to each position will require re-adjusting.
The filter wheel controller responds to RS232 commands and requires software to control its operation. An optional manual
mode uses a push-button switch to step sequentially through the filter positions.
3. OPERATION
3.1 Mounting
Mounting of the wheel itself is via 1/4-20 threaded holes (if provided) located on the sides of the filter wheel housing or via
a mounting flange (or flanges) on the front and/or back of the housing.
Due to the vast possibilities of mounting arrangements, custom modification of the filter wheel housing may be necessary.
Modified hardware will not be accepted by Spectral Products for full refund. If replacement is deemed necessary, Spectral
Products will try to re-use modified parts, but is under no obligation to duplicate customer custom modifications. Mounting
hole patterns and flange dimensions are provided in Specifications; Mechanical.
3.2 Filter Installation
Access to the filters is provided by removing four screws to remove the cover of the filter wheel housing.
Filters may be held in place by whatever means suit the customer’s application. A popular method is to use small dabs of
silicone RTV on the edge of a filter to “tack” the filter in place.

Spectral Products
2659-A Pan American Frwy., NE Albuquerque, NM 87107 Tel [phone] Fax [phone]
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3.3 Connections
The filter wheel housing to filter wheel controller connection is made via a DB9-F to DB9-M cable (Spectral Products pn:
DK12AT, provided.) The connection is from the controller port “To Filter Wheel” to the filter wheel housing.
The host computer to filter wheel controller connection is made via a standard RS232 cable (not a “Null-Modem” type) to
the “RS232 In” port on the filter wheel controller.
The power supply connects to the filter wheel controller at the “Power” jack.

Spectral Products
2659-A Pan American Frwy., NE Albuquerque, NM 87107 Tel [phone] Fax [phone]
www.spectralproducts.com
4. PROGRAMMING
4.1 Overview
The AB300-Series controller responds to software commands via the RS232 connector. This communication may come
from any device capable of RS232, utilizing any language and operating system. The AB300-Series controller is a DCE
device and uses the following protocol:
8 Data bits, 1 Stop bit, No Parity
Baud is user programmable (factory shipped configured at 9600)
Flow control is via hardware handshaking (utilizing CTS and RTS)
Hardware handshaking for the AB300-Series controller is employed as follows:
CTS (from controller to host) signals if the controller is ready to receive a byte over the RS232 line. If the CTS
line is asserted (ie, a positive voltage) the controller is ready to receive. If a byte(s) is sent while CTS is deasserted
(ie, a negative voltage) the character may be lost. As the AB300-Series controller has a one character input buffer,
multiple characters or commands cannot be received and stored. Since CTS is held deasserted while the filter
wheel is executing a command, the reassertion of CTS signals that the command has completed.
RTS (from host to controller) signals if the host is ready to receive a byte(s) from the controller. The AB300-
Series controller does check this handshaking line and will wait indefinitely for RTS to be asserted before sending
a character. For this reason, the host system must ensure RTS is asserted for the filter wheel to work properly.
DTR, DCR, and DCD are not used by the AB300-Series controller; however, some PC serial ports require that
these lines be used. Normally, tying these pins together at the PC COM port will allow CTS/RTS handshaking to
work.
Proper handling of hardware handshaking is vital to smooth operation. Each programming language has different methods
and defaults for this protocol which must be understood by the programmer.
The filter wheel controller is designed to be the sole device on an RS232 line. If multiple devices are desired and serial
ports are not available, a serial port switch box may be used (contact Spectral Products for details and suggestions on
multiple filter wheel systems.)
4.2 Commands
The communication to and from the controller utilizes bytes (8 bits). Each command consists of one or more bytes sent
from the host to the controller. Depending on the command, one or more bytes may be returned by the controller to return
data or signify the end of a command.
Commands should be sent as indicated, without sending terminating characters (for example, do not send carriage return at
the end of each command.) Undesired characters may have an adverse affect on controller operation.
For the following, a value surrounded by angle brackets ,< >, is the decimal (base 10) value of byte transmitted. Typical
programming practice would be to send and receive these bytes as ASCII characters, converting them to a decimal value as
needed by other programming tasks. How this is done is dependent on the language used. Refer to the sample programs for
examples.
For commands that return a “Status Byte,” that byte is interpreted as follows;

Bit Meaning
7 (MSB) 0 if command accepted
6 1 if value specified = current value
5 0 = value too high, 1 = value too low (ignore if bit 7 = 0)
4 0 = moving to lower filter, 1 = moving to higher filter
3 - 0 Not used
The commands and their protocol are described as follows (in alphabetical order):
4.2.1 Baud
To controller: <58>,<Baud Rate Byte>
From controller: <Status>,<24>
Action: Baud rate switched to new rate after <24> sent
Baud rate bytes are as follows;
Byte Baud Byte Baud
0 9600 4 600
1 4800 5 300
2 2400 6 150
3 1200 7 75
Note: The controller saves the last selected baud rate and will use that rate at the next power on or RESET.
Therefore, the user must also remember the last baud rate. Powering the AB300-Series controller off, then on, will
not reset the baud rate.
4.2.2 Echo
To controller: <27>
From controller: <27>
Action: None
The ECHO command is used to verify communication.
4.2.3 EEPROM Read
To controller: <56>,<Address Byte>
From controller: <Data High Byte>,<Data Low Byte>,<Status Byte>,<24>
Action: None
Reads the word (two bytes) value currently stored in EEPROM non-volatile memory at the specified address (0 -
15.) The two returned data bytes form a word as follows;
(<Data High Byte>
× 256) + <Data Low Byte> = Word
Spectral Products
2659-A Pan American Frwy., NE Albuquerque, NM 87107 Tel [phone] Fax [phone]
www.spectralproducts.com

Spectral Products
2659-A Pan American Frwy., NE Albuquerque, NM 87107 Tel [phone] Fax [phone]
www.spectralproducts.com
4.2.4 EEPROM Write
CAUTION! Improper or indiscriminate use of this command may impair the functionality of the instrument.
Caution and discretion are advised!
To controller: <59>,<Address Byte>,<Data High Byte>,<Data Low Byte>,
<Checksum Byte>
From controller: <Status Byte>,<24>
Action: Data written to EEPROM address
Writes a word (two bytes) to the EEPROM non-volatile memory at the specified address (0 - 15.) The value of the
word is given by
(<Data High Byte>
× 256) + <Data Low Byte> = Word
The “Checksum Byte” must be correct for the write to be allowed, and is determined by
(Address + Data High Byte + Data Low Byte) mod 256 = Checksum
where Checksum is a byte long (i.e. modulo-256) and any carry is ignored. If the checksum byte is not correct, the
command will be IGNORED (no status or <24> will be sent.)
This command is normally not used except at the factory.
4.2.5 Go to New Filter Position
To controller: <15>,<Position Byte>
From controller: <Status Byte>,<24>
Action: Filter wheel moves to specified position
Valid positions are 1-6 (AB301), 1-5 (AB302), or 1-12 (AB303). If position is valid, the wheel turns to the new
position. If invalid, no movement occurs and status byte signals problem.
4.2.6 Query Position
To controller: <29>
From controller: <Position Byte>,<Status Byte>,<24>
Action: None
QUERY POSITION will return the present filter position in “Position Byte.” (e.g. 1, 2, 3... decimal, not ASCII
character “1”, “2”, “3”.)

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4.2.7 Reset
To controller: <255>,<255>
From controller: Nothing
Action: Filter wheel re-homes and goes to filter position 1.
This command effectively does a power-on reset, resetting the controller board and re-homing the wheel. It is
used when there is suspicion the wheel has lost track of where it physically is (in the event of jamming, for
example.) In normal use this command should not be needed. It may, however, be used periodically for “just in
case” reassurance that the wheel position is correct.
Since this command does not return a value, knowing when it completes requires an alternate strategy. One
method is to monitor the CTS line from the filter wheel controller. It will be de-asserted while the RESET is in
progress, and asserted when done and ready for another command (as is standard for RS232 devices utilizing
hardware flow control.)
Another way is to send the ECHO command and wait for the echo byte back. If it doesn’t come, repeat the
process. This method is preferable only if hardware flow control isn’t available.
4.2.8 Step Down
To controller: <1>
From controller: <Status Byte>,<24>
Action: Wheel moves one motor step toward next lower position
Used to fine adjust the current position. For filter one, it may be used preceding a ZERO command to set the
default filter one position.
4.2.9 Step Up
To controller: <7>
From controller: <Status Byte>,<24>
Action: Wheel moves one motor step toward next higher position
Used to fine adjust the current position. For filter one, it may be used preceding a ZERO command to set the
default filter one position.
4.2.10 Zero
To controller: <52>
From controller: <Status Byte>,<24>
Action: Current position is saved as filter one default location
Sets the default filter one position. All other filter positions are derived from this location. The wheel must be set
to filter position one prior to issuing this command.
CAUTION: Failure to select filter position one prior to using this command may cause erratic or unpredictable
results, including failure to operate. Care and discretion are advised.

Spectral Products
2659-A Pan American Frwy., NE Albuquerque, NM 87107 Tel [phone] Fax [phone]
www.spectralproducts.com
5. OPERATION HINTS
Using RESET to close the loop on position: As part of the power on reset the filter wheel finds home by sensing a switch
closure. This switch sensing is the only feedback the controller gets regarding actual physical position. From that point on
the wheel is controlled “open loop.” If for any reason the wheel loses its position (e.g. the wheel jams or becomes
disconnected), the controller will not be able to tell a problem exists.
It may be desirable or at least reassuring to “close the loop” by having the wheel re-find its home position. This is done by
issuing the RESET command.
Using QUERY position: After power on or the RESET command a filter wheel goes to the filter one position. All
subsequent movements from there are done by issuing FILTER commands. So, theoretically at least, the controlling
software should always know the current filter position of any filter wheel.
Still, it may be reassuring to query the filter wheel controller to verify what it thinks is the current position matches what
the controlling software thinks. This is done with the QUERY command. Note, the filter wheel is positioned “open loop”
and cannot tell if a malfunction has prevented the wheel from reaching its desired target. For example, if a wheel became
unplugged from the controller, no error would occur using FILTER commands, and a QUERY would return the intended
position, not the actual filter position (which is long lost.) Only the RESET command will detect the problem by failing to
home.
If the optional manual advance switch has been used, QUERY will return the correct current filter position, barring any
problems as described above. Therefore the controlling software may be re-synchronized to the correct position.
Fine tuning each position: Only the filter one position has a programmable “fine tuning” adjustment that is saved. For
filter one position only, this is done by using STEP UP and STEP DOWN, then issuing a ZERO command to store the
setting. All other filter positions are a fixed number of steps from the filter one position.
Fine tuning of each filter position may be accomplished using software techniques. The process is to go to a filter position,
then issue STEP UP/DOWN commands to fine tune the position. The number of STEP UP/DOWN commands needed
must be handled (saved) by the controlling software. Each time that position is to be recalled, a FILTER # and the
appropriate number of STEP would be issued.
Note: Adjusting a position using STEP does not affect the “base” position of subsequent positions (E.g.: Using 3 step up
commands for filter 2 does not make the subsequent filter 3 position off by 3 steps.)

6. SPECIFICATIONS
6.1 Mechanical
6.1.1 AB301, 1 Inch Aperture, 6 Position
0.97
1.89
#6-32 (2 plcs)
4.343 0.586 0.586
2.187
0.586
0.586
#6-32 (2 plcs)
See below for
hole pattern
4.375
5.500
4.343
2.187
0.97
Flange
1.66
Thin cover
Thick cover
Not to Scale
* Flange is compatible with Spectral Products’ Digikröm
monochromators.
Spectral Products
2659-A Pan American Frwy., NE Albuquerque, NM 87107 Tel [phone] Fax [phone]
www.spectralproducts.com

6.1.2 AB302, 2 Inch Aperture, 5 Position
* Threaded flange is Thorlabs 2” tube compatible.
Threaded Flange
2.35
1.97
0.97
Not to Scale
6-32
1/4-20
0.44
3.750
0.780
1.625
2.470
7.50
7.25
4.470
3.625
2.780
Spectral Products
2659-A Pan American Frwy., NE Albuquerque, NM 87107 Tel [phone] Fax [phone]
www.spectralproducts.com

5.1.3 AB303, ½ Inch Aperture, 12 Position
1.85
4.375
5.500
5.03 0.97
1.66
Spectral Products
2659-A Pan American Frwy., NE Albuquerque, NM 87107 Tel [phone] Fax [phone]
www.spectralproducts.com
4.375
Not to Scale

5.1.4 AB304-T, 1 Inch Aperture, 12 Position
Base Dimensions
7.5
Spectral Products
2659-A Pan American Frwy., NE Albuquerque, NM 87107 Tel [phone] Fax [phone]
www.spectralproducts.com
7.25
6.375
3.625
Cover Dimensions
7.5
.586
1.125
.586
3.625
.586
.586
01.00
THRU

6.2 Electrical
6.2.1 RS232 In
DB9 pin Signal Direction
2 RxD From controller to computer
3 TxD From computer to controller
5 GND Signal Ground
7 RTS From computer to controller
8 CTS From controller to computer
The AB300-Series controller RS232 port (a DCE device) should be connected to a computer (DTE device) via a standard
“straight through” cable (not a null modem type.) Connector is numbered.
6.2.2 Power
GND
Tip: +12 VDC, 800mA max
Shaft: Ground return
6.2.3 Filter Wheel +V
Pinout applies at wheel assembly and controller. Connectors are numbered.
DB9 Pin Function
1 Motor Coil; Yellow
2 Motor Coil; Brown
3 Motor Coil; Red
4 Motor Coil; Black
5 Motor Coil; White
6 Motor Coil; Orange
7 Home Contact
8 Home Contact
9 N/C
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Spectral Products
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Computer to filter wheel RS232
RS232: DB9-F to DB9-M, for 9 pin serial DTE to AB300-Series
From DB9-F pin To DB9-M pin
1 1
2 2
3 3
4 4
5 5
6 6
7 7
8 8
9 9
RS232: DB25-F to DB9-M, for 25 pin serial DTE to AB300-Series
From DB25-F pin To DB9-M pin
8 1
3 2
2 3
20 4
7 5
6 6
4 7
5 8
22 9
6.2.4 Filter wheel assembly to filter wheel controller
Spectral Products pn DK12AT, motor drive cable for AB300-Series
From DB9-F pin To DB9-M pin
1 1
2 2
3 3
4 4
5 5
6 6
7 7
8 8
9 9
If the Spectral Products-supplied cable is not used, we recommend that the cable use 26 AWG or larger wire, be shielded,
and not exceed 12 feet in length.