Commissioning
EL3783
107
Version: 1.1
5.3
Basic function principles
RMS value (rms) specifications
All AC value specifications in this documentation such as RMS specifications (
rms
) refer to a 50/60
Hz 3-phase mains network with a sinusoidal waveform.
Introduction
The EL3783 has 6 analog input channels which are measured simultaneously in their respective measuring
ranges. The 3 analog input channels for current measurement have different measuring ranges. These can
be set via CoE or selected automatically by the EL3783 on the basis of the momentary measured values.
Each channel has an anti-aliasing low-pass filter with a limit frequency of 5.5 KHz. However, the high
sampling rate of 20 KSps also allows frequency components up to higher than 9 KHz to be detected.
Further information is available upon request.
Using the sample programs
This document contains sample applications of our products for certain areas of application. The
application notes provided here are based on typical features of our products and only serve as ex-
amples. The notes contained in this document explicitly do not refer to specific applications. The
customer is therefore responsible for assessing and deciding whether the product is suitable for a
particular application. We accept no responsibility for the completeness and correctness of the
source code contained in this document. We reserve the right to modify the content of this docu-
ment at any time and accept no responsibility for errors and missing information.
Automatic current range switching
The EL3783 features automatic current range switching. This can be configured via the sub-indices in object
During a switching event, processes within the terminal lead to measured data lying outside the specified
accuracy for about 250 µs. This short-term inaccuracy is signaled to the PLC via Object
.
Depending on the application there must be a reaction to this on the software side.
In order to use this function, it must be activated via the CoE object "
configured as desired. Various dynamics are pre-programmed according to which the switching takes place
quickly (Dynamic 0) or slowly (Dynamic 3).
The following sample project (see appendix) shows amongst other things how a conversion of the PDO
values can be carried out, including automatic range switching.
Sample program (https://infosys.beckhoff.com/content/1033/el3783/Resources/zip/3264881931.zip)
Declaration of variables and source code:
„
EL3783_HCBorderCnt := 0;
EL3783_5ARange := FALSE;
CF := 1.8415054;
FOR i:= 0 TO 19 DO
IF i = EL3783_HCRange[EL3783_HCBorderCnt] THEN
EL3783_5ARange := NOT EL3783_5ARange;
IF EL3783_5ARange THEN
CF := 9.207527;
ELSE
CF := 1.8415054;
END_IF
EL3783_HCBorderCnt := EL3783_HCBor 1;
END_IF
EL3783_UL1_DC20[i] := INT_TO_LREAL(EL3783_UL1_DC_020[i])
* 737.2575 / 32768;
EL3783_UL2_DC20[i] := INT_TO_LREAL(EL3783_UL2_DC_020[i])
* 737.2575 / 32768;
EL3783_UL3_DC20[i] := INT_TO_LREAL(EL3783_UL3_DC_020[i])
