def subprocess_command(exp='xpptut15', run='0260', procname='pixel_status', qname='psnehq',\
                       dt_sec=60, sources='cspad,opal,epix100,pnccd,princeton,andor') :
    """Returns command like 'proc_control -e xpptut15 -r 0260 -p pixel_status -q psnehq -t 60 -s cspad,pnccd'
    """
    if procname == 'pixel_status' :
        return 'proc_control -e %s -r %s -p %s -q %s -t %d -s %s' %\
                             (exp, str(run), procname, qname, dt_sec, sources)
    else :
        return None