Technical data

Software
System Manual, 07/2009, C79000-G8976-C222-07
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Glossary
Alarm logging (runtime)
Alarm Logging controls the acquisition and archiving of events and provides display and
operator input options. Using the message blocks, message class and message type
structure elements, the configuration engineer can class the events according to their
significance and allow the operator a fast evaluation of the status of the system.
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.
APN - Access Point Name
DNS host name of the access point for an external network (in this case: access point in the
GPRS network to the Internet).
Automation program
The automation program is the program section on the CPU that monitors and controls the
technological process.
COM port
→ RS-232
Command
A command is binary information that is transferred once as a 1 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 a 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).