Beckhoff ELX3351, Operating Manual

Page: 57 / 71

Parameterization and programming
ELX3351 57 Version: 1.3.1
Bit - meaning of the Status Word
Bit SW.15 SW.14 SW.13 SW.12 -
SW.9
SW.8 SW.7 SW.6 SW.5 -
SW.4 SW.3 SW.
2 SW.1 SW.
0
Name TxPDO Tog-
gle - - - Steady State Calibra-
tion in
progress Error - Data invalid - Over -
range -
Meaning toggeles
0->1->0 with
each up-
dated data
set - - - Idling recogni-
tion Calibra-
tion in
progress Collective
error dis-
play - Input data
are invalid - Measuring
range ex-
ceeded -
Bit - purpose of the variable Value (Real)
Bit position (from left) 1 8 23 (+1 "hidden bit", see IE559)
Function Sign Exponent Mantissa
Bit - meaning of the Control Word
Bit CW.15 -
CW.5 CW.4 CW.3 CW.2 CW.1 CW.0
Name - Tare - Input Freeze Disable Calibration Start Calibration
Meaning - starts tare - stops the measurement switches the automatic self-cali-
bration off starts the self-calibra-
tion immediately
5.5.3 Variants Predefined PDO
Floating-point representation of the load
The display of the load value can also be converted already in the terminal into a point representation. To do
this the input PDOs are to be changed as follows:
Fig. 48: Load value in floating-point representation
Variable Meaning
Value
(Real) calculated 32-bit floating point REAL load value with mantissa and exponent in unit [1]
The format matches the REAL format of IEC 61131-3, which in turn is based on the REAL format
of IEC 559. A REAL number (single precision) is defined as follows (See also
Beckhoff InfoSys:
TwinCAT PLC Control: standard data types ). According to IEC61131, this 32-bit variable can be
linked directly with a FLOAT variable of the PLC, see "Bit – meaning of the variable value
(REAL)"