Siemens SIMATIC S7 CP340 Programming Manual page 63

5 MODBUS RTU Protocol communication
Fig. 114: Distribution of MODBUS Slave addresses
6. FC01, 05, 15: status of read and forced output bit. The left side is info transfer
address, and the right side is corresponding PLC address area, viz. the left
addresses from 0 to 23 match MODBUS address area 00001 to 00024, and the
corresponding Siemens data area is M0.0-M2.7.24 to 47 match the MODBUS
Address area 00025 to 00048, and the corresponding Siemens data area is Q0.0
to Q2.7.Slave addresses 48 to 79 and 80 to 111 match the Modbus address areas
00049 to 00080 and 00081 to 00112, and the corresponding Siemens data area is
Timer, Counter. FC02 reads input data status, and the address matching is as
stated above.
Fig. 115: Distribution of MODBUS Slave addresses
7. FC03,06,16 configuration output register data area corresponds to Siemens
data area DB block.
CP340/CP341/CP440/CP441 Communication and Programming
Entry-ID: 88867653, V1.0, 02/2014
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