Siemens SIMATIC S7 Manual page 33

Parameter Decl.
start _3 IN
end _3 IN
data_type_4 IN
db _4 IN
start _4 IN
end _4 IN
data_type_5 IN
db _5 IN
start _5 IN
end _5 IN
data_type_6 IN
db _6 IN
start _6 IN
end _6 IN
data_type_7 IN
db _7 IN
start _7 IN
OPEN MODBUS / TCP communication via CP343-1 and 443-1
2XV9450-1MB00; Manual edition 4.3
Type Description
WORD 3rd data area: first Modbus address in this DB
WORD 3rd data area: last Modbus address in this DB
BYTE 4th data area: data type (Coils, Inputs,
Holding Register, Input Register),
NULL if not used
WORD 4th data area: data block number
WORD 4th data area: first Modbus address in this DB
WORD 4th data area: last Modbus address in this DB
BYTE 5th data area: data type (Coils, Inputs,
Holding Register, Input Register),
NULL if not used
WORD 5th data area: data block number
WORD 5th data area: first Modbus address in this DB
WORD 5th data area: last Modbus address in this DB
BYTE 6th data area: data type (Coils, Inputs,
Holding Register, Input Register),
NULL if not used
WORD 6th data area: data block number
WORD 6th data area: first Modbus address in this DB
WORD 6th data area: last Modbus address in this DB
BYTE 7th data area: data type (Coils, Inputs,
Holding Register, Input Register),
NULL if not used
WORD 7th data area: data block number
WORD 7th data area: first Modbus address in this DB
Function Block MODBUSCP
Value range
0 to 65535
W#16#0000 to
W#16#FFFF
0 to 65535
W#16#0000 to
W#16#FFFF
0 to 4
1 to 65535
W#16#1 to
W#16#FFFF
0 to 65535
W#16#0000 to
W#16#FFFF
0 to 65535
W#16#0000 to
W#16#FFFF
0 to 4
1 to 65535
W#16#1 to
W#16#FFFF
0 to 65535
W#16#0000 to
W#16#FFFF
0 to 65535
W#16#0000 to
W#16#FFFF
0 to 4
1 to 65535
W#16#1 to
W#16#FFFF
0 to 65535
W#16#0000 to
W#16#FFFF
0 to 65535
W#16#0000 to
W#16#FFFF
0 to 4
1 to 65535
W#16#1 to
W#16#FFFF
0 to 65535
W#16#0000 to
W#16#FFFF
Init
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
5-5