Scanner selection

If the variable pulseq_scanner is not specified in your sequence creation script before pulseq_init, your default scanner will be selected.

Default scanner

The default scanner is set when you first run install_OpenMRF.m. It can be changed later by modifying the corresponding field in user_specifications/user_definitions/pulseq_user_definitions.csv.

You can compile a sequence for a scanner that is not set as your default by explicitly setting the variable pulseq_scanner to the name of an alternative scanner. See the following example. Assume the default scanner is set to 'Siemens_Sola_1,5T_MIITT'.

pulseq_mrf.m
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%% init pulseq
clear
seq_name = 'mrf_';

% optional flags
flag_backup = 0; % 0: off,  1: only backup
flag_report = 0; % 0: off,  1: only timings, 2: full report (slow)
flag_pns    = 0; % 0: off,  1: simulate PNS stimulation
flag_sound  = 0; % 0: off,  1: simulate gradient sound
flag_mrf    = 0; % 0: off,  1: simulate sequence via MRF toolbox

% init system, seq object and load pulseq user information
pulseq_init();
This will set the system specifications to the values defined in user_specifications/system_definitions/Siemens_Sola_1,5T_MIITT.csv.

pulseq_mrf.m
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%% init pulseq
clear
seq_name = 'mrf_';

% optional flags
flag_backup = 0; % 0: off,  1: only backup
flag_report = 0; % 0: off,  1: only timings, 2: full report (slow)
flag_pns    = 0; % 0: off,  1: simulate PNS stimulation
flag_sound  = 0; % 0: off,  1: simulate gradient sound
flag_mrf    = 0; % 0: off,  1: simulate sequence via MRF toolbox

pulseq_scanner = 'Siemens_FreeMax_0,55T_MIITT';

% init system, seq object and load pulseq user information
pulseq_init();
This will set the system specifications to the values defined in user_specifications/system_definitions/Siemens_FreeMax_0,55T_MIITT.csv.

Scanner selection

Never run a sequence on a scanner that it was not compiled for. While your scanner should usually detect if a sequence exceeds certain limits, this can't be guaranteed, and you risk damaging your system.