IDN Notation Format

IDN 1  Numeric Cycle Time

The cycle time of the numeric controller (TNcyc). This time corresponds to IDN 2, which specifies the SERCOS cycle time (TScyc).

Note:

Not all IDN descriptions require all the fields listed above. Only the applicable fields are filled within an IDN description. The field definitions are as follows:

IDN x

The identification number in short-hand notation. 

S-x-xxxx / P-x-xxxx

According to IEC 61491 specified notation of a SERCOS identification number.
S-x-xxxx are SERCOS standard-specific identification numbers, versus P-x-xxxx are product-specific ones.

Title

A descriptive title of the IDN (in above case it is: Numeric Cycle Time).

Description

Information of the IDN purpose and relations/dependencies to other IDN's are named here. 

Data Length

The length of IDN element 0 resp. 7, in bytes. Possible entries for this field are as follows:

Data Type

The format for interpreting and displaying the operating data. Possible entries for this field are binary, unsigned decimal, signed decimal, hexadecimal, text and IDN.

Minimum / Maximum

The allowed range of IDN element 7 data. IDN element 7 is checked for range compliance in the service channel. In general, if the range is blank in the IDN description, this means that IDN elements 5 and 6 are not supported. The ranges of some IDNs are dependent upon the value of other IDNs, drive parameters or motor parameters.

Default

The default value for IDN element 7 data. An IDN will revert to its default value after a firmware upgrade. The default may be a fixed value, or it may be stored in non-volatile memory. A blank “Default” field indicates that the IDN does not have a default value.

Units

The units of IDN element 7 data and of the minimum, maximum, and default fields. The units of some IDNs are obtained from the operating data of other IDNs. IDNs of data type “binary”, “text”, or “IDN” do not have units and the “Units” field is left blank in the IDN description.

Non-Volatile

Indicates whether the IDN operation data can be saved in non-volatile memory. Possible entries for this field are as follows:

(blank)     - The operating data is stored in volatile memory and is lost when logic power is removed.
Yes           - The operating data may be stored in non-volatile memory and will be retained after power down.

Write Access

The SERCOS communication phases (CPx) during which an IDN may be written. In general, an IDN may be read through the service channel during communication phases CP2 and above. However, writing to an IDN may be restricted during some communication phases or while the drive is enabled. An entry of “Read-only” indicates that the IDN cannot be written during any communication phase.

Run-Up Check

The SERCOS communication phases (CPx) during which the validity of the operating data is checked. Possible entries for this field are as follows:

Cyclic Transfer

Indicates whether cyclic transfer is possible for IDN element 7. Possible entries for this field are as follows:

Serial Equivalent

An equation of equivalent protocol commands that may be issued through the RS-232/485 serial port (e.g., through the Microsoft Windows® HyperTerminal program to be started with:  Start | Run ... type hypertrm.exe) to obtain the IDN data. The contents of the IDN can be obtained by evaluating the equation. The field is blank in the IDN description if no equivalent serial commands are available.

Version

The drive Firmware version from which on this IDN is supported.

IDN Type

The

IndexGroup

Names the ADS IndexGroup to use for accessing this IDN via ADS in a hexa-decimal format. The IndexOffset, which is also necessary for the ADS command, specifies the required element from this SERCOS IDN in this context. The IndexOffset (IdxOffs) to use, varies from case to case.

IndexOffset specification: 

TwinCAT PLC contains a function block library (TcSystem.lib) for the ADSREAD and ADSWRITE access of objects accessible via the ADS protocol.