Siemens SIMATIC S7-300 Manual page 105

Parameters
1. Tag of a → Code block
2. Tag used to set one or several properties of a module. Each module is supplied with
Process image
The CPU saves the signal states of analog IO modules to a process image.
We distinguish between the process image of inputs (PII) and outputs (PIO). The input
modules read the process image of inputs (PII) before the operating system executes the
user program. The operating system transfers the process image of outputs (PIO) to the
output modules at the end of program execution.
Product version
Differentiates products of the same order number. The product version is incremented in the
case of upwards compatible enhancements of functionality, production-specific changes (use
of new components/parts), and fixes.
Reaction to open thermocouple
STEP 7 parameter for analog input modules operating with thermocouples. This parameter
defines whether the module outputs an "Overflow" (7FFFH) or "Underflow" (8000H) value
when it detects an open thermocouple.
Reference potential
Potential from which the voltages of participating circuits are derived and measured.
Resolution
Number of bits representing the value of analog modules in binary format. The resolution is
module-specific. It is also determined by the → integration time of analog input modules. The
precision of the measured value resolution increases with the length of the integration time.
The maximum resolution is 16 bits + sign.
SFC
→ System Function
Signal module
Signal modules (SMs) form the interface between the process and the automation system.
These are available as digital and analog input/output and IO modules.
SM 335 - High-speed analog mixed module for SIMATIC S7-300
Manual, 02/2009, A5E02409063-01
default parameters which users may edit in
STEP 7
.
Glossary
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