retrieve Modbus connection header length.
res = modbus_getHeaderLength(mbc)
The modbus connection created with modbus_newTcp or modbus_newRtu
the length of Modbus message header.
modbus_get_header_length retrieve Modbus connection header length.
mbc = modbus_newTcp("127.0.0.1", 502); modbus_getHeaderLength(mbc) modbus_free(mbc);