FPΣ User's Manual 
 
8.6 Program Controlled Communication 
211 
The status of the "reception done" flag may change while a scan is being carried out. For 
example, if the flag is used more than once as an input condition, different statuses may exist 
within one scan. To ensure proper execution of the program, the status of the special internal 
relay should be copied to a variable at the beginning of the program. 
 
Buffer statuses 
The following shows the statuses of the send and receive buffers when the sample program is 
run. 
Status of the send buffer before sending: 
16#53 16#25(S) (%)
20
1
Offset
 
At the end of transmission, the value in offset 0 is automatically reset to 0. 
Status of the receive buffer when the reception is completed: 
DT200
16#30DT201
DT202
DT203
DT204
16#31(0) (1)
16#32 16#31(2) (1)
16#34 16#33(4) (3)
16#35 (5)
7
 
The number of bytes received is stored in offset 0. The received data is stored in order from 
the low-order byte. 
 
8.6.6.2  1:1 Communication with FP Series PLC 
Connect the FPΣ and another FP series PLC using the RS232C interface and the 
MEWTOCOL-COM communication protocol. 
 
NOTE
 
MEWTOCOL-COM Master/Slave mode is recommended over program controlled 
mode since programming is easier. 
"%01#RDD00000 00001**
C
R
" 
Communication mode:
Program controlled
Communication mode: 
MEWTOCOL-COM
Data area read command
Value of specified data register
FP series PLCFP series PLC
 
1:1 communication between the FPΣ (left) and another FP series PLC (right)