Sample Program 11 (Scripts For Generation And Transformation Of Filter Coefficients); Sample Program 12 (R/W Signature Of Calibration); Fig. 39 Seek The Generated Data Type Of Smpdovariables - Beckhoff EPP3504-0023 Short Manual

Commissioning
Fig. 39: Seek the generated data type of SmPdoVariables
The variables declaration within the function block FB_REALTIME_DIAGNOSIS then contains:
st_SM2 AT%Q* : ECAT_ELM3602_0002_SM_3412CB6A;
st_SM3 AT%I* : ECAT_ELM3602_0002_SM_87A01A51;
The read access to the inputs of the application is provided via the structure st_SM3 and write access to the
outputs via the structure st_SM2. These data structures corresponds to the automatically added new PDO
element "SmPdoVariables".
4.3.10 Sample program 11 (scripts for generation and
transformation of filter coefficients)
Download link:
https://infosys.beckhoff.com/content/1033/epp3504/Resources/12455432203/.zip
For explanations of application see chapter "Exemplary calculation of IIR/FIR filter coefficients".
4.3.11

Sample program 12 (R/W signature of calibration)

The box module features an advanced calibration mechanism to store, among other things, an individual
signature with 256 bytes, which results from the calibration data. In this way the customer could provide a
calibration with a specific signature, e.g. to detect unauthorized internal manipulation of the calibration data;
see also chapter "Display of data changes".
The function block described below can be used as a basis for an implementation in TwinCAT on a PLC. To
simplify matters, only a CRC16 was used in this sample to serve a "signature" limited to two bytes. At a
commented point in the FB implementation, another signature algorithm can be implemented, which can be
up to 256 bytes long.
The sample function block is included in the TwinCAT 3 archive, which is available for download together
with a visualization:
https://infosys.beckhoff.com/content/1033/epp3504/Resources/8823639307/.zip
Explanatory notes for the visualization "Calibration_Signature_RW"
The input variables of the ADS address and the "InputToggle" must be linked again if another terminal or Box
(than ELM3602) is used for the sample. This must be entered in the field after starting the sample program.
Alternatively, it can be entered before the start as initialization of the input variable "sTerminalTypeIn" of the
function block "FB_VisuUpdate":
sTerminalTypeIn : T_MaxString := 'ELM3602';
After the program start
The function block "FB_CalibrationSignature" is called in read mode by the visualization when channel +/- or
interface +/- or "read" is actuated and in write mode when "write" is actuated. If, after reading, the calculated
and the read signature match, bCmpResult becomes TRUE (no inequality). After a write access the entry
remains in the read CoE and can be checked by reading (a write access does not change the state of
bCmpResult).
114 Version: 1.2 EPP3504-0023