Using The Busy Line; Using The Error Line; Using A Computer's Parallel (Printer) Port - Sutter Instrument LB10-3 Operation Manual

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8.4.3 Using the BUSY Line

8.4.3 Using the BUSY Line
8.4.3 8.4.3 Using the BUSY Line Using the BUSY Line
Reading the status of the BUSY
is ready to receive a command, if a command has been received, and when the new filter has
been placed in position. Obviously, it is also possible for the host computer to control the
timing of events based on the expected behavior of the LAMBDA 10
using the BUSY BUSY line only to verify that the controller is in the expected state. BUSY BUSY
The status of the BUSY BUSY line could also be used as a condition for timing other events. For
BUSY BUSY
instance, the dropping of the BUSY
beginning data collection. Using the BUSY
for time required to recover time from errors. The BUSY
indication that an error has occurred. If the BUSY
after a new command was issued, it may be assumed that the controller has detected an error
and the filter wheel is in the process of recovering.
8.4.4

8.4.4 Using the ERROR Line

8.4.4 8.4.4 Using the ERROR Line Using the ERROR Line Using the ERROR Line
The ERROR ERROR ERROR ERROR line signals when an ERROR
ERROR line normally would not be used to determine timing of program execution in the ERROR ERROR ERROR
host computer, since it is active only after an error and, even then, it is not held high during
the entire ERROR recovery process. The use of the ERROR
What are the consequences of an error? What are the consequences of an error? What are the consequences of an error? Continuing normal program execution in the What are the consequences of an error?
host computer during recovery from an error might cause problems such as wasted data
storage, exposure of sensitive photo detectors, experimental preparation to strong light;
or the recording of faulty data.
What is the burden placed on the host computer in checking the ERROR line. What is the burden placed on the hos
What is the burden placed on the hos What is the burden placed on the hos
ERROR ERROR line will go high only after a move that has been completed incorrectly, and will
ERROR ERROR
remain high only during part of the recovery from that error. Thus, the host computer
would have to read the status of the ER
collection should begin.
8.5

8.5 Using a Computer's Parallel (Printer) Port

8.5 8.5 Using a Computer's Parallel (Printer) Port Using a Computer's Parallel (Printer) Port Using a Computer's Parallel (Printer) Port
The standard PC parallel port provided for printer control may be used to control the
LAMBDA 10 0 0 0 - - - - 3 3 3 3 . This, however, does not mean that instructions can be sent to the LAMBDA LAMBDA 1 LAMBDA 1 LAMBDA 1
10- - - - 3 3 3 3 in the same manner that they are sent to a printer. A printer is designed to print at its 10
10 10
maximum rate and, if the computer generates output at a higher rate, the printer will store
the output in a buffer until the mechanism is ready. If the buffer becomes full, the printer
will indicate to the computer that it is not ready to accept more data. It follows that there is
not a tight time relationship between the output of a command from the computer and the
execution of that command by the printer.
The time relationship between output of data from the computer and response by the
LAMBDA 10 LAMBDA 10 LAMBDA 10- - - - 3 3 3 3 , in contrast, must be very tight. Thus, it is understandable that the mode LAMBDA 10
with which the parallel port is used will differ somewhat for the LAMBDA 10
printer.
The details of the input and output signals were described in previous sections. Now we will
discuss the way in which these signals may be used to control the LAMBDA
computer's parallel printer port. This information is provided as a limited example and is
BUSY line would allow the host computer to determine if the unit
BUSY BUSY
BUSY BUSY BUSY line could be used as the trigger for opening a shutter or
BUSY line to trigger other events automatically allows BUSY BUSY
BUSY BUSY BUSY line fails to go low at the expected time
ERROR in Filter Wheel movement has been detected. The ERROR ERROR
t computer in checking the ERROR line. The
t computer in checking the ERROR line. t computer in checking the ERROR line.
ER ERROR ER ROR line just at the point in time at which data ROR ROR
LAMBDA 10-3 OPERATION MANUAL – REV. 3.03 (20110829)
LAMBDA 10 LAMBDA 10- - - - 3 3 3 3 (as described above) LAMBDA 10
BUSY line can even be used as an BUSY BUSY
ERROR line will depend on two factors ERROR ERROR
LAMBDA 10- - - - 3 3 3 3 from that of a LAMBDA 10 LAMBDA 10
LAMBDA 10 LAMBDA LAMBDA
LAMBDA LAMBDA LAMBDA
10- - - - 3 3 3 3 from a PC 10 10