5 MODBUS RTU Protocol communication
CP340/CP341/CP440/CP441 Communication and Programming
Entry-ID: 88867653, V1.0, 02/2014
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Fig. 70: Logic address of CP341
3. Invoke MODBUS Slave function block
LADDR
Start logic address in hardware configuration,
which is 256 in this example
START_TIME
timeout initialization timer, which is T1 in this
example
START_TIME
timeout initialization time value, which is 1s in
this example
OB_MASK
I/O access error mask bit, which is M100.0 in
this example
CP_START
FB initialization enable bit, which is M100.1 in
this example
CP_START_FM
CP_START initialization rising edge bit, which is
M100.2 in this example
CP_START_NDR
write from CP operation bit, which is M100.3 in
this example
CP_START_OK
initialization succeed flag, which is M100.4 in
this example
CP_START_ERROR
initialization fail flag, which is M100.5 in this
example
ERROR_NR
error number, which is MW102 in this example
ERROR_INFO
error message, which is MW104 in this
example. Refer to Modbus Slave Manual -
Chapter 10
Table 12: Parameter definition of FB80