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Glossary
Analog value
An analog value is an analog process variable such as pressure, temperature etc. It is
acquired over an analog input as a current or voltage value and converted by this module to
a binary-coded value. In total, the converted value occupies 1 word; in other words, 16 bits
including sign bit.
Automation program
The automation program is the program section on the CPU that monitors and controls the
technological process.
COM port
RS-232 is a standard for serial (i.e. bit-by bit) data transmission with +12 V and -12 V
signals. RS-232 is a Recommended Standard of the Electronic Industries Association. For
the RS-232 interface, 9-pin and 25-pin connections with D-sub connectors are normal.
These are sub-miniature connectors with a D-shaped face.
Command
A command is binary information that is transferred once when there is a signal change from
0 to 1. The trailing edge from 1 to 0 does not trigger transmission again. At the receiving end,
a command is either output as a pulse (selectable duration) or it is reset by the local user
program after it is has been executed. 8 commands are put together to form a byte.
When inputting and outputting commands, reliability and safety are important. At the input
end, for example, there is a check to determine whether only one command is pending at the
time of acquisition (1-out-of-n check). Only then is the transmission triggered. If several
commands are pending at the same time, an error is detected. There is no transmission. To
transmit 1 command byte, a total of 1 word is used: One "original" command byte and a
copy. At the receiving end, a command is only output when the "original" command byte and
the copy have the identical content and when only 1 command was received (once again a
1-out-of-n check).
Configuration
During configuration, communication- and connection-specific system settings are made for
each device.
SINAUT ST7 Station control system - System Manual
System Manual, 05/2007, C79000-G8976-C178-06
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