When used in master-slave (or synchronized-start) mode, the modules are to be connected such that one module (the master) gates others (the slaves). There can be only one master, but there is no limit on the number of slaves.

Other than the limitation that there can only be one master, the other configuration options can be freely mixed in the same set up.

FUNCTIONS

When configured as a 1D MCA-type device, the DAQ-ATDC/NDAQ is controlled by spec's MCA functions, such as mca_get() and mca_par(). See the mca help file for details. When configured as 2D device, the DAQ-ATDC/NDAQ is controlled by spec's image functions, image_get() and image_par().

The mca_get() (or mca_sget()) and image_get() functions retrieve data from the DAQ- ATDC/NDAQ module. The mca_par() (or mca_spar()) and image_par() functions control the module behavior as follows. The sel parameter is the MCA- or image-device number from the config file. The functions mca_get() and mca_par() use the currently selected MCA device chosen by the mca_sel() function.

mca_get(arr)

mca_sget(sel, arr)

image_get(sel, arr)

Reads data into the array arr. The native data type is ulong.
 In image mode, when acquisition is active, the device returns a 256x256 preview image. However, image_get() must still be called with an array dimensioned to the full resolution of the device. spec will place the preview image in the first 256 columns and rows of the array.

mca_par("reset")

mca_spar(sel, "reset")

image_par(sel, "reset")

Resets the USB endpoints and the DSP. Note, the modules are always reset during hardware initialization at start up and on a reconfig. This command shouldn't be needed during normal operation.

mca_par("mirror")

mca_spar(sel, "mirror")

image_par(sel, "mirror")

Returns one or zero, depending on whether mirror mode is set.

mca_par("mirror", value)

mca_spar(sel, "mirror", value)

image_par(sel, "mirror", value)

Turns mirror mode on or off depending on whether value is nonzero or zero. Mirror mode is only available in synchronized-start mode when one module is configured as master and others as slaves. In mirror mode, the slave modules are programmed with the same acquisition parameters as the master, and the slave presets are set to zero, which means the slaves will count as long as gated by the synchronization signal from the master.

mca_par("update")

mca_spar(sel, "update")

image_par(sel, "udpate")

Updating the parameters on the DAQ-ATDC modules (not the NDAQ) takes a couple of seconds. For maximum efficiency, spec only writes the parameters if one or more have changed. The parameters will be updated to the module, if necessary, before the modules are started. To avoid a delay when starting the modules, the "update" option can be sent to ensure the parameters are current. If operating in synchronized-start mode and the "mirror" parameter is set, the slave modules will be updated with the same operating parameters as the master.

mca_par("clear")

mca_spar(sel, "clear")

image_par(sel, "clear")

Clears the current data. If operating in synchronized-start mode with master and slaves, if called for the master, the slaves will be cleared also.

mca_par("run")

mca_spar(sel, "run")

image_par(sel, "run")

Starts data collection. If operating in synchronized-start mode with master and slaves, if called for the master, the slaves will be started also. In addition, if auto-clear (clear-on- start) mode is enabled, data on both master and slaves will be cleared.

mca_par("halt")

mca_spar(sel, "halt")

image_par(sel, "halt")

Halts data collection.

mca_par("npts")

mca_spar(sel, "npts")

Returns the current number of points in 1D configuration.

mca_par("npts", value)

mca_spar(sel, "npts", value)

Sets number of points in 1D configuration. Legal values for the parameter are 256, 512, 1024 and 2048.

image_par(sel, "resolution")

Returns the the current resolution value in 2D configuration.

image_par(sel, "resolution", value)

Sets resolution in 2D configuration. Legal values for the parameter are 256, 512, 1024 and 2048.

image_par(sel, "bits")

Returns the current value of the image bits parameter.

image_par(sel, "bits", value)

Sets the image bits parameter. This parameter is used to reduce the number of bits in the raw data arriving from the TDC input. A value of 12 results in a 4096x4096 array, a value of 11 results in a 2048x2048 array, and so on.

mca_par("preset_mode")

mca_spar(sel, "preset_mode")

image_par(sel, "preset_mode")

Returns "counts" or "time" according to the current preset mode.

mca_par("preset_mode", value)

mca_spar(sel, "preset_mode", value)

image_par(sel, "preset_mode", value)

Sets the preset mode to time if value is the string "time" or has the number value of zero. Sets the preset mode to counts if value is the string "counts" or has a nonzero number value.

mca_par("preset")

mca_spar(sel, "preset")

image_par(sel, "preset")

Returns the current preset value. The value is in seconds if the current preset mode is "time" or counts if the current preset mode is "counts".

mca_par("preset", value)

mca_spar(sel, "preset", value)

image_par(sel, "preset", value)

Set the preset value to the specified number of seconds if the current preset mode is "time" or to the specified number of counts if the current preset mode is "counts".

mca_par("elapsed_time")

mca_spar(sel, "elapsed_time")

image_par(sel, "elapsed_time")

Returns the elapsed time in seconds of the most recent data acquisition. The command can be used while acquisition is in progress.

mca_par("elapsed_counts")

mca_spar(sel, "elapsed_counts")

image_par(sel, "elapsed_counts")

Returns the elapsed counts of the most recent data acquisition. The command can be used while acquisition is in progress.

mca_par("offset_x")

mca_par(sel, "offset_x")

image_par(sel, "offset_x")

Returns the x-offset parameter for the ATDC module.

mca_par("offset_x", value)

mca_spar(sel, "offset_x", value)

image_par(sel, "offset_x", value)

Sets the x-offset parameter for the ATDC module to value.

image_par(sel, "offset_y")

Returns the y-offset parameter for the ATDC module, which is only useful in 2D mode.

image_par(sel, "offset_y", value)

Sets the y-offset parameter for the ATDC module to value, which is only useful in 2D mode.

mca_par("bin_time")

mca_par(sel, "bin_time")

image_par(sel, "bin_time")

Returns the ATDC bin time in picoseconds.

mca_par("bin_time", value)

mca_spar(sel, "bin_time", value)

image_par(sel, "bin_time", value)

Sets the ATDC bin time to value. Allowed values are 110, 120, 130, 140 and 150. spec will choose the value closest to the value passed as an argument.

mca_par("gate")

mca_par(sel, "gate")

image_par(sel, "gate")

Returns the gate value for the ATDC module in nanoseconds.

mca_par("gate", value)

mca_spar(sel, "gate", value)

image_par(sel, "gate", value)

Sets the ATDC gate to value, with units of nanoseconds. The valid range is from 100 to 500.

mca_par("emulation")

mca_spar(sel, "emulation")

image_par(sel, "emulation")

Returns zero or one to indicate whether emulation mode is on. In emulation mode, the DAQ-ATDC/NDAQ module generates an artificial data set.

mca_par("emulation", value)

mca_spar(sel, "emulation", value)

image_par(sel, "emulation", value)

Sets emulation mode on or off according to whether the argument is nonzero or zero.

mca_par("dump")

mca_spar(sel, "dump")

image_par(sel, "dump")

Displays most of the DAQ-ATDC/NDAQ parameters. This command can be used while acquisition is in progress.

USAGE

The following example shows how to take data in 2D mode and display the data using the 2D display program onze from the ESRF (and downloadable at certif.com/downloads/extras/onze ).