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Knauer pump RS232 communication

Knauer pump RS232 communication

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Functions for communicating with Knauer pumps via RS232.

knauerpumpobjwriteminpress(serialObject, minPress, pumpHeadSize)
function knauerpumpobjwriteminpress(serialObject, minPress, pumpHeadSize)
% KNAUERPUMPTCPOBJWRITEMINPRESS sets minimum pressure of Knauer pumps
% knauerpumpobjwriteminpress(serialObject, minPress, pumpHeadSize)
% changes the minimum pressure of Knauer pumps (where the pump will stop
% pumping automatically) given a valid serial object and a pressure from 0
% to 400 bar.  The function automatically rounds the minimum pressure to
% the nearest integer.  If no pump head size is supplied, it will try and
% retrieve it, but if one is supplied, then will retrieve the maximum
% pressure set for that pump head size.

% e.g. knauerpumpobjwriteminpress(serialObject, 250) - sets minimum
% pressure of the pump to 250 bar

% Range:

% serialObject = valid serial object

% minPress = unsigned number: 0-400


% checks the number of arguments
error(nargchk(2, 3, nargin))

% if a pump head size was supplied...
if nargin >= 3
    
    % check the input
    if ~isvalidknauerpumpheadsize(pumpHeadSize)
        
        % complain
        error('Must supply a valid pump head size - 10 or 50 [mL].')
    end

else
    
    % fetch it
    pumpHeadSize = knauerpumpobjreadpumpheadsizefast(serialObject);
end

% depending on what the pump head size is, different pressures are possible
switch pumpHeadSize
    
    case 10
        
        % its 400 bar
        maxPossiblePress = 400;
        
    case 50
        
        % its 150 bar
        maxPossiblePress = 150;
        
    otherwise
        
        % issue a warning
        warning('Unknown pump head size for Knauer pump - unable to check pressure against maximum pressure.')
        
        % define it as infinite so its not really checked
        maxPossiblePress = inf;
end

% error handling
if ~isscalar(minPress) || ~isreal(minPress) || isnan(minPress) || minPress < 0 || minPress > maxPossiblePress
    
    % errors
    error('Maximum pressure must be a number from 0 to %d bar', maxPossiblePress)
end

% checks the minimum pressure
if minPress ~= round(minPress)
    
    % display a warning (don't actually need to round it off as the sprintf
    % will deal with that)
    warning('KnauerPumpWriteMinPress:ValueTooPrecise', 'Supplied minimum pressure was not an integer so has been rounded off.')
end

% forms and writes command
knauerpumpobjcomm(serialObject, 'write', sprintf('PMIN%d:%.0f', pumpHeadSize, minPress))

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