DESCRIPTION

The Nicomp TC-100 Autocorrelator is selected in the config file as

RS_TC100 = /dev/ttyXX  baud_rate

When running edconf (or the config macro), use the MCAs section of the Devices screen to select the Nicomp autocorrelator.

FUNCTIONS

The mca_par() function controls the correlator behavior as follows:

mca_par("clock")

returns the value of the current clock time parameter in microseconds.

mca_par("clock", value)

sets the clock time parameter. The units for value are microseconds. Valid clock times are of the form X.XeY where X.X ranges from 0.1 to 1.6 and Y ranges from 0 to 5. Values outside these bounds will be rounded to the closest allowed value. The new value takes effect on the next run command.

mca_par("prescale")

returns the value of the prescale factor.

mca_par("prescale", value)

sets the value of the prescale factor. Valid prescale values are from 1 to 99. The new value takes effect on the next run command.

mca_par("dbase_mode")

returns the state of the baseline mode. A return value of 1 means delayed baseline mode is in effect. A return value of 0 means delayed baseline mode is off.

mca_par("dbase_mode", 1|0)

sets the state of the baseline mode. A value of 1 turns on delayed-baseline mode. A value of 0 turns it off. The new mode takes effect on the next run command.

mca_par("dbase")

returns the value of the delayed baseline from the last data obtained using mca_get().

mca_par("cbase")

returns the value of the calculated baseline from the last data obtained using mca_get().

mca_par("tcnts")

returns the value of the total-counts monitor channel from the last data obtained using mca_get().

mca_par("pcnts")

returns the value of the total-prescaled-counts monitor channel from the last data obtained using mca_get().

mca_par("rtime")

returns the value of the run-time monitor channel from the last data obtained using mca_get() in seconds.

mca_par("clear")

clears the correlator.

mca_par("run")

sends the current clock-time, prescale and delayed-baseline parameters to the correlator and starts the correlator. The tcount() and mcount() functions also start the correlator.

mca_par("halt")

stops the correlator. The correlator is also halted when count intervals specified by tcount() or mcount() have elapsed, or when counting is aborted using a ^C.

mca_par("plot")

reads off the real-time data plot from the running correlator. The data obtained is a very low resolution version of the correlation function.

mca_get(g, e)

reads the current data from the correlator, and stuffs the data into the data group g element e.

MACROS

clr

clears the correlator.

run

starts the correlator.

halt

stops the correlator.

get

reads the correlator data and plots it.

clk [clock_time]

sets the clock time. The macro prompts for a value if it is not given as an argument.

pre [prescale_factor]

sets the prescale factor. The macro prompts for a value if it is not given as an argument.

dbase [0|1]

sets delayed-baseline mode. The macro prompts for a value if it is not given as an argument.

cbase

prints the value of the calculated baseline from the last data read.

ct [count_time]

accumulates correlation function for count_time seconds. Plots the data at the end of count_time.

uct [count_time]

accumulates correlation function for count_time seconds. Updates a low resolution display of the correlation function while counting.

qelsplot

does a screen plot of the current data using labels appropriate for a correlation function.

qelsfile

saves the current data to the datafile. After the data points are saved, two lines of information are saved as

#U2 clock_time prescale cbase dbase

#U3 dbase_mode tcnts pcnts rtime

where the parameters are, in order: the clock time, the prescale factor, the values of the calculated and delayed baselines, a zero or one to indicate if the delayed baseline was used, the total counts, the total prescaled counts and the elapsed time from the correlator.