Station control system
System Manual, 07/2009, C79000-G8976-C178-07
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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.
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
→
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).
Conditional spontaneous message
In the dial-up network, you can specify whether or not a change causes a "conditional
spontaneous" or "unconditional spontaneous" transmission for each individual message.
Conditional spontaneous messages are initially only entered in the send buffer of the TIM.
They are only transmitted when a connection is established to the partner for whatever
reason, for example because an unconditional spontaneous message needs to be
transmitted or because the partner calls.
