Rules of the address transformation

The address that is used internal by the Applicom corresponds to a 4 byte integer number and a function. Since this is rather unpractical for configuration, a specific protocol-dependent address is transformed into this Applicom address via a protocol-dependent translation table. The user can address protocol-specific as usually. The transformation rules (format transformation of the peripheral address between the device-specific format and the internal Applicom format) are saved in an own file. This allows to adapt the rules for new protocols. See the Online help for the transformation rules between the Applicom and the protocol-specific address. You have to define specific entries in this file for each protocol that should be supported by the driver.

Note

If a specific protocol is not available in this file the rules for Applicom addresses (e.g. READBIT.1)can be used. (These rules are defined in the beginning of the file.) This means that a general not protocol-dependent address is used for the peripheral addresses. This is however not recommended because protocol-specific differences are not taken into account. See Applicom Online Help for more information on this protocol.

Note

Note that only specialists, who have experience with drivers, peripheral devices and specific protocols, should change the file. Before you change the file copy it into the  <proj_path>/config directory and make the desired changes.

The file with the transformation rules apc_config  is saved in the <wincc_oa_path>/config directory.

In the following you can find an example of a protocol that is defined in the apc_config file. The example describes the structure and the function of the file.

INDUSTRIAL_ETHERNET_S7_300

The file contains the following entries for the INDUSTRIAL_ETHERNET_S7_300 protocol.

[INDUSTRIAL_ETHERNET_S7_300]

#

MAX_BIT_READ=1769

MAX_BYTE_READ=222

MAX_WORD_READ=111

MAX_DWORD_READ=55

MAX_FWORD_READ=55

#

WORDDISP=2

DWORDDISP=4

#

RWBIT=Ma.b;a*8+b;;BIT

RWBIT=DBa.DBXb.c;a*524288+b*8+c;;BIT

READIBIT=Ea.b;a*8+b;;BIT

RWQBIT=Aa.b;a*8+b;;BIT

RWBYTE=MBa;a;;BYTE

RWBYTE=DBa.DBBb;a*65536+b;;BYTE

READIBYTE=EBa;a;a;BYTE

RWQBYTE=ABa;a;a;BYTE

RWWORD=MWa;a;;WORD

RWWORD=DBa.DBWb;a*65536+b;a*256+b;WORD

READIWORD=EWa;a;;WORD

RWQWORD=AWa;a;;WORD

RWDWORD=MDa;a;;DWORD

RWDWORD=DBa.DBDb;a*65536+b;;DWORD

RWFWORD=MDaF;a;;FWORD

RWFWORD=DBa.DBDbF;a*65536+b;;FWORD

The first lines (starting from MAX) define the maximum number of elements for a data type that can be read in a request or in a cyclic function from the periphery.

The entry MAX_BIT_READ=1769 shows the maximum number (1769) of bits that can be handled in a read request. The maximum number of floating-point numbers in one request is 55 for the entry MAX_FWORD_READ=55. If the maximum number is exceeded a new cyclic function is created on the Applicom card. The entries for the single data points were taken from the Applicom documentation.

Additionally there are two entries for the Industrial Ethernet S7-300 and S7-400 protocols. The entries are called WORDDISP and DWORDDISP. The entries specify how many address increments 16bit words or 32bit words need. This setting results from the different word addressing for S5 and S7. The address of S5 is "word-oriented" and the address of S7 is "byte-oriented". Equivalent addresses are:

The other lines describe the transformation types and rules for the different functions of the INDUSTRIAL_ETHERNET_S7_300 protocol and have the following syntax:

Function name = protocol-specific addressing; simple formula; DB access; transformation type

The entry READIBIT=Ea.b;a*8+b;;BIT means consequently:

The function is READIBIT (a bit -input- is read from the periphery).  Ea.b is the addressing with a specific industrial Ethernet S7-300 protocol. (E means input, a and b are variable and an addressing could take place e.g. with E4.5). a*8+b is the address transformation rule which generates an independent Applicom address from the specific peripheral address (e.g. an independent address 37 is generated for the address E4.5). The next entry (DB access) is not defined for the function that is defined here. An address in the interface database is defined via the entry for the DB access. The address is used for spontaneous data (the S7-300 could normally send spontaneous bits but the Applicom does not support this and this entry is therefore not defined for bits). The last definition BIT specifies the transformation type.

The entry RWWORD=DBa.DBWb;a*65536+b;a*256+b;WORD means:

The function is RWWORD (you can read an Integer16 from the periphery resp. write to the periphery). DBa.DBWb is the addressing with the specific Industrial Ethernet S7 300 protocol (a and b are variable and an addressing could e.g. take place  with DB3.DBW7). a*65536+b is the rule for address transformation and generates an independent Applicom address from the specific peripheral address. The address for accessing the interface DB is defined with a*256+b (for the protocol-specific DB3.DBW7 it would be the place number 775 in the address range of the interface DB). WORD defines the transformation type of this function. For detailed information on the transformation types see chapter Details on the Applicom driver.

On the basis of the function names you can see the file section of the interface DB where you are located. RWWORD would e.g. be in the Word section and READIBIT again in the bit section. If only bits are mapped as spontaneous data in the interface DB these are ,of course, in the bit section after the transformation.

Note

Spontaneous bytes are not supported when using a S7. Bytes have to be transmitted in words! Entries with the letters "RW" signify, whether an I/O peripheral address is allowed for a PLC address (of course for the specific protocol).

Note

Spontaneous addresses that exceed the interface DB (this means addresses that exceed the address range after the transformation via the appropriate formula) may not exist. See also chapter Access functions and polling for the description of the interface DB. If there are spontaneous addresses in the PLC these have to be placed in the lower part.

The addressing in the configuration panel for the peripheral address of a data point element (data type float) is protocol-specific and could look like this:

Figure: Configured Applicom peripheral address