EL32xx settings

The following chapters list the necessary and optional settings for taking temperature or resistance measurements with the EL32xx:

Basic settings	Sensor type 0x80n00:19 Connection method 0x80n0:1A
Further settings (optional)	PDO presentation 0x80n00:02 Compensation of the supply line resistance 0x80n0:1B User scaling 0x80n00:01 Calibration and calculation of process data: user calibration 0x80n00:18/17 and manufacturer calibration 0x80nF Siemens bits 0x80n00:05 Notch filter 0x80n00:06 and conversion times (not for EL3214, EL3208 and EL3218) Limit 1 0x80n00:13, Limit 2 0x80n00:14 (not for EL3214, EL3208 and EL3218)

Notice

Mixed operation of low-impedance and high-impedance sensors within a terminal operating in multiplex mode must be avoided!

Due to large differences in resistance between the sensor types, mixed operation of low-impedance sensors, e.g. Pt/Ni, and high-impedance sensors, e.g. NTC, within a terminal should be avoided if the terminal operates in multiplex mode, i.e. channels are read in successively by an ADC. In this case, larger measuring errors can occur for the low-resistance sensors.
Alternatively, 1-channel or simultaneously operating devices (each channel has its own ADC) should be used, since no changeover processes occur here.

Notice

RTD basics

The RTD basics in chapter "Basics of RTD technology" of the IO Analog Manual and "RTD measurement in EL32xx" must be observed.

Overarching orientation is provided by the data flow, the successive processing steps from the ADC converter to the process data output to EtherCAT:

Data flow

The terminal permanently records measured values and puts the filtered raw values X_ADC of the A/D converter into the ADC raw value object 0x80nE:01.
After each acquisition of the analog signal, the correction calculation is performed with the calibration values, measured value after calibration:
Y_calibrated = ((ADC raw data / 8) - Calibration offset) * Calibration gain * 2^-18
optional: Wire calibration
optional: Transformation RTD element R [Ohm] -> T [°C]
If user scaling is activated (0x80n0:01 = TRUE) the measured value is calculated including user scaling: Y_scaled = (Y_calibrated * A_W * 2^-16) + B_W
Otherwise Y_scaled = Y_calibrated
Application "Presentation
optional: limit evaluation
Measured value output to EtherCAT

Changes of the slave parameters in the CoE directory

The CoE parameters may have to be changed in the "CoE online" tab of the EtherCAT slave during commissioning.

EL32xx settings 3: — Accessing the CoE parameters in TwinCAT System Manager, EL3201

For detailed information on settings and operation modes, please read the following chapters on Basic settings and "Further settings (optional)".

	Reset the terminal If an EL32xx which was already configured in use is to be put into operation, it is recommended that the settings in the CoE be reset to the factory settings if necessary (see chapter "Restoring the delivery state")

Notice

Changes in the CoE directory (CAN over EtherCAT), program access

When using/manipulating the CoE parameters observe the general CoE notes in chapter "CoE interface" of the EtherCAT system documentation:

Keep a startup list if components have to be replaced,
Distinction between online/offline dictionary,
Existence of current XML description (download from the Beckhoff website),
"CoE-Reload" for resetting the changes
Program access during operation via PLC (see TwinCAT3 | PLC Library: Tc2_EtherCAT and Example program R/W CoE)

Further Information