5 Configuration of the fieldbus node in the master

5.1 Identification Code

In the ID cycle which is carried out for the initialization of the Interbus system, the users connected users are identified by their function and their byte length. The Interbus S coupler identifies its length after being started in the initialization phase of the bus modules and forms a corresponding ID code. To this effect each slave has an implemented identification register (ID register) comprising 2 bytes.

A 2 byte wide data unit is called a word. It enables the encoding of 65536 different states. In Interbus S, different types of users and data widths are called for the coding. This enables the master to find out what type the device belongs to, which means for

example, recognizing either frequency inverters or I/O units, like the :$*2Ç, 2Ç6<67(0 In Interbus S the manufacturers of device types are not

recognized. The structure of the ID code is explained below as well as the significance of the individual bits of the ID code.

The length information can be coded from 0 to 32 words:

messages

data width

class of user

type of user

data direction I, O, I/O

Table 2: Structure of the Interbus ID code

-In the ID registers, the device group is coded in the lowest value (LSB) 8 bits (ID 0 to 7).

-In the following 5 bits (ID 8 to 12), the data width is coded. The 3 bits with the highest value (MSB) (ID 13 to 15) are used for management functions. Via these bits, dynamic fault messages are transferred during operation. These bits are not defined by the hardware.

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5.2ID Code for WAGO I/O System

Due to the combined use of digital, analog and special functions on one fieldbus station and with the given structure of the Interbus ID codes, it is impossible to manage with one ID code.

The WAGO Interbus S buscoupler is identified as a digital slave with variable length!

Table 3: ID codes for the WAGO Interbus S buscoupler

For the master, it is important to know how many data registers each user assigns in the Interbus S system. If a user has, for example, 16 bits of input and 32 bits of output, he assigns 2 words in the bus because there are 2 words of output. In this case the higher value of data width is decisive. The data width is coded by the bits ID 8 to ID 12 as shown in section 5.1.

The following table shows the register widths depending on the function modules connected to a WAGO Interbus S buscoupler.

Possible values for data length are::

[x]: is used [xx]: is used and firmware 3.20 or PC driver 2.0 or later is combined

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