Communication 
 
FPΣ User's Manual 
176 
 
NOTE
 
•  If no response is returned, the command may not have arrived at the slave, 
or the slave may not be functioning. Check to make sure all of the 
communication specifications (e.g. baud rate, data length, and parity) match 
between the master and the slave. 
•  Station number and command name are always identical in a command and 
its corresponding response (see below). This makes the correspondence 
between a command and a response clear. 
%01#RC
C
R
%01$RC
C
R
 
1
 
Command message 
2
Response message 
 
8.5.3 Commands 
 
Command name  Code  Description 
Read contact area 
RC 
(RCS) 
(RCP) 
(RCC) 
Reads the on and off status of contacts. 
- Specifies only one point. 
- Specifies multiple contacts. 
- Specifies a range in word units. 
Write contact area 
WC 
(WCS) 
(WCP) 
(WCC) 
Turns contacts on and off. 
- Specifies only one point. 
- Specifies multiple contacts. 
- Specifies a range in word units. 
Read data area 
RD  Reads the contents of a data area. 
Write data area 
WD  Writes data to a data area. 
Read timer/counter set value area 
RS  Reads the value set for a timer/counter. 
Write timer/counter set value area 
WS  Writes a timer/counter setting value. 
Read timer/counter elapsed value area 
RK  Reads the timer/counter elapsed value. 
Write timer/counter elapsed value area 
WK  Writes the timer/counter elapsed value. 
Register or Reset contacts monitored 
MC  Registers the contact to be monitored. 
Register or Reset data monitored 
MD  Registers the data to be monitored. 
Monitoring start 
MG  Monitors a registered contact or data using MD and MC. 
Preset contact area (fill command) 
SC  Embeds the area of a specified range in a 16-point on and 
off pattern. 
Preset data area (fill command) 
SD  Writes the same contents to the data area of a specified 
range. 
Read system register 
RR  Reads the contents of a system register. 
Write system register 
WR  Specifies the contents of a system register. 
Read the status of PLC 
RT  Reads the specifications of the PLC and error codes if an 
error occurs.