PLCObject : Ensure that PreStart is executed before starting PLC. Also, make sure that python thread doesn't enter in a start/stop loop when ordered to stop.
<xsd:attribute name="Command" type="xsd:string" use="optional" default="make -C %(buildpath)s all BEREMIZSRC=%(src)s BEREMIZCFLAGS=%(cflags)s MD5=%(md5)s USE_BEREMIZ=1 FROM_BEREMIZ=1"/>