Make Modbus mutexes non blocking for PLC. If data related to some modbus request is alredy locked when PLC wants to access it, then data isn't copied to/from PLC
<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"/>