{HEAD ~ The serial data transmission unit} 2, wherein said value read from the program by said CPU is determined considering a longest one of data holding intervals of {TAIL ~ said plurality} of external slaves 
{ HEAD ~ The serial data transmission unit } 2 , wherein said value read from the program by said CPU is determined considering a longest one of data holding intervals of { TAIL ~ said plurality } of external slaves
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH