Technical data

Glossary
Software
System Manual, 07/2009, C79000-G8976-C222-07
457
Setpoint
A setpoint is a selected digital or analog value that is transmitted once after the value has
been set. The entered value is recalculated when necessary. A setpoint is always
transmitted as 1 word. At the receiving end, the setpoint can either the output directly to the
process as an analog signal (for example to an external controller) or the value is made
available to the local program for further processing (setpoint for internal controller, limit
value, threshold value etc.).
Setpoint and command input are interlocked for safety reasons; in other words, a setpoint
input cannot be made at the same time as a command input. In this case, the acquisition
program recognizes an error. Neither the setpoint nor the command are transmitted.
SIM card
(Subscriber Identity Module)
The SIM card is an identification card for a subscriber of a GSM mobile wireless network.
SIMATIC S7
Siemens automation system
Simple Internet communication
In SINAUT ST7, simple Internet communication means data exchange between TCP/IP-
compliant devices in Ethernet, landline or mobile wireless networks using the → MSC
protocol.
SINAUT
(SIemens Network AUTomation)
Station control system or telecontrol system based on SIMATIC S7
SINAUT message
An ST7 message contains the data of an ST7 object for transmission. Depending on the
object type, a message can contain either all data of an ST7 object or only a contiguous
subarea of the object data.
SINAUT object
A SINAUT object contains the data of one or more process variables such as analog values,
commands, calculated values, status information on motors, sliders etc. An ST7 object has
type-specific processing functions and change checks assigned to it to minimize the
communication traffic in the WAN. Type-specific processing functions include, for example,
threshold checks or mean value calculation with the object type for analog values. The
change check is designed so that a message is generated only when the object data has
changed compared with the last time its value was transferred or when the type-specific
processing enables generation of a message because the object data is "worth" transferring.