RadioProcessor-G
III. Creating Custom Pulse Programs
Getting Started
The quickest way to become acquainted with writing programs for your RadioProcessor-G board is to go through the
example programs included with the MRI SpinAPI Examples package, which can be found on the SpinCore website at
http://spincore.com/products/RadioProcessor-G/
. It includes three example programs that demonstrate the
functionality of the RadioProcessor-G. The .c code for these files contain descriptions of the programs.
Procedure for Writing a Pulse Program
The RadioProcessor-G is a highly versatile excitation and acquisition system, and as a result there are
many possible approaches to programming the board; however, most applications will follow six basic steps:
1. Initialize the MRI SpinAPI.
2. Load the frequency and phase registers with desired values, and define the shape of carrier and
envelope signals.
3. Specify data acquisition related parameters.
4. Specify all parameters that control the timing of the experiment, i.e., pulse times, delays, etc.
5. Trigger the pulse program. The experiment will then proceed autonomously.
6. Retrieve the captured data from the board at any time without interrupting the acquisition process.
These steps are described in detail below. Please note that all of the functions described in this manual
are also detailed in the MRI SpinAPI Reference Manual, which is included in the MRI SpinAPI software
package available from the RadioProcessor-G product page on the SpinCore website.
Step 1: Initialize MRI SpinAPI
Before the parameters for a pulse program can be written, the MRI SpinAPI must be initialized by calling
these two functions:
spmri_init()
spmri_set_defaults()
Step 2: Define RF Output Parameters
In order to output an RF signal, the phase, frequency, amplitude and shape of a carrier signal and an envelope signal
must be defined. The actual RF output is produced by multiplying these two signals together. The amount of registers
available is detailed in Table 2 below.
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Table 2:
Available DDS registers.
Register Bank
Number of Registers
Carrier Frequency
16
Carrier Phase
16
Envelope Frequency
8
Amplitude
4
