Siemens Simatic S7 Series User Manual

50
Analog Output Example Analog outputs from a PLC are often supplied directly or
through signal converters or transmitters to control valves,
instruments, electronic drives or other control devices which
respond to analog signals.
For example, analog outputs from the PLC could be used to
control the flow of fluid in a process by controlling AC drives.
Rather than simply turning the AC drives on or off, which could
be accomplished by discrete outputs, analog signals can be
used to control the output of the AC drives. This would allow
the speed of the pumps to be varied dynamically in response to
changes in process requirements.
Central
Processing
Unit
(CPU)
Analog
Input
Analog
Outputs
PLC
Signal from
Level Transmitter
To Pump 1
To Pump 2
AC Drives
Level
Transmitter
Pump 1
Pump 2
Storage
Tank
Process
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Siemens Simatic S7 Series Specifications

General

CPU	Varies by model (e.g., S7-300, S7-400, S7-1200, S7-1500)
Communication Interfaces	PROFIBUS, PROFINET, Ethernet, MPI
Programming	TIA Portal, STEP 7
Programming Languages	LAD, FBD, STL, SCL, GRAPH
I/O Modules	Digital, Analog, Specialty modules available
Operating Temperature	0°C to 60°C (standard models)
Mounting	DIN rail mounting
Operating Voltage	24V DC or 120/230V AC (varies by model)
Protection Class	IP20 (standard models)
Memory	Varies depending on the S7 model. Includes work memory (RAM) for program execution, load memory (EEPROM or Flash) for program storage, and system memory for operating system functions. Memory sizes range from kilobytes to megabytes.