PerkinElmer LS 55, User Manual

Page: 129 / 202

RS232 Commands . 129
Sample Acquisition Accessories
There are 4 types of sample acquisition accessory available: the peristaltic pump,
the four-position cellchanger, the plate reader and the biokinetic accessory.
• The peristaltic pump may be driven in either direction for a period of time
specified in units of 0.1 seconds. Pumping may be aborted at any time by the
user.
• The four-position cellchanger may be driven to position. The cellchanger may
be fitted with coils driving magnetic stirrer bars. The stirrer speed may be set
to one of three values: off; low; high.
• The plate reader can be used to read samples from a well plate, a TLC plate or
a gel. For a well plate, the plate reader takes a reading at each well. For a TLC
plate or gel, the plate is scanned in the x or y direction, starting at specified
co-ordinates.
• The biokinetic accessory enables the temperature of the cell to be measured.
It also has a stirrer as in the four-position cell holder (above) and the facility for
event marking.
The Sipper, cell holder, and plate reader accessories require initialization before
they are used. Initialization is required each time they are plugged into the
instrument or if any operation is performed that changes the motor position(s)
other than under control of the instrument. Explicit initialization commands are
available. The instrument software automatically initializes accessories if a
command to move a fitted accessory is issued and the accessory has not been
initialized since it was last plugged in. An error is reported from accessory control
commands if the accessory becomes unplugged at any time before or during the
command or if the software initialization is unsuccessful.
Fast Filter Accessory (FFA)
Fast rotating filter units for excitation and emission can be fitted in place of the
excitation filter/polarizer wheel and emission polarizer wheel. The FFA units are
synchronized with the source flash and fluorescence data collection cycle. Data
points are collected and output for each filter position at a rate controlled by the
$FI command. The maximum data output rate is one point or filter position per
fluorescence data collection cycle (mains cycle). Data collection is not possible in
modes other than fluorescence.
The FFA units are controlled by a separate microprocessor board fitted with the
existing VME boards. When FFA units are signaled fitted by the bit switch settings
detailed on page 102, control signals are passed between the CPU and FFA control
board via the ports usually used for the excitation filter/polarizer wheel and
emission polarizer wheel accessory. If the bit switches are not set correctly
inappropriate signals will be sent by the CPU and the accessories will not function.