Libraries
9.3 Modbus library instructions
S7-200 SMART
452 System Manual, 09/2015, A5E03822230-AC
Holding register addresses greater than 49999
Modbus holding addresses are within the range of 40001 to 49999. This range is adequate
for most applications but there are some Modbus slave devices with data mapped into
holding registers at a higher address range.
The MBUS_MSG instruction allows an additional range for the parameter
to support an
extended range of holding register addresses at addresses 400001 to 465536.
For example: to access holding register 16768, the
parameter of MBUS_MSG should
be set to 416768.
The extended addressing allows access to the full range of 65536 possible addresses
supported by the Modbus protocol. This extended addressing is only supported for holding
registers.