Simatic Step7 - 300

Features
• Modular small control system for the lower performance range
• Performance-graded range of CPUs
• Extensive selection of modules
• Expandable design with up to 32 modules
• Backplane bus integrated in the modules
• Can be networked with - Multipoint interface (MPI),
- PROFIBUS or
- Industrial Ethernet.
• Central PG/PC connection with access to all modules
• No slot restrictions
• Configuration and parameter setting with the help of the "HWConfig" tool.

Simatic Step7 - 300 Modules

Signal Modules (SM)
• Digital input modules: 24 VDC, 120/230 VAC
• Digital output modules: 24 VDC, Relay
• Analog input modules: Voltage, current,
resistance, thermocouple
• Analog output modules: Voltage, current

Interface Modules (IM)
The IM360/IM361 and IM365 make multi-tier configurations possible. The interface modules loop the bus from one tier to the next.

Dummy Modules (DM)
The DM 370 dummy module reserves a slot for a signal module whose parameters have not yet been assigned. A dummy module can also be used, for example, to
reserve a slot for installation of an interface module at a later date.

Function Modules (FM)
Perform "special functions":
-Counting
- Positioning
- Closed-loop control.

Communication Processors (CP)
Provide the following networking facilities:
- Point-to-Point connections
- PROFIBUS
- Industrial Ethernet.

Accessories
Bus connectors and front connectors

Simatic Step7 CPU Design

Mode Selector
MRES = Memory reset function (Module Reset)
STOP = Stop mode, the program is not executed.
RUN = Program execution, read-only access possible from PG.
RUN-P = Program execution, read/write access possible from PG.

Status Indicators (LEDs)
SF = Group error; internal CPU fault or fault in module with diagnostics capability.
BATF = Battery fault; battery empty or non-existent.
DC5V = Internal 5 VDC voltage indicator.
FRCE = FORCE; indicates that at least one input or output is forced.
RUN = Flashes when the CPU is starting up, then a steady light in Run
mode.
STOP = Shows a steady light in Stop mode.
Flashes slowly for a memory reset request,
Flashes quickly when a memory reset is being carried out,
Flashes slowly when a memory reset is necessary because a
memory card has been inserted.

Memory Card
A slot is provided for a memory card. The memory card saves the program
contents in the event of a power outage without the need for a battery.

Battery Compartment
There is a receptacle for a lithium battery under the cover. The battery provides
backup power to save the contents of the RAM in the event of a power outage.

MPI Connection
Connection for a programming device or other device with an MPI interface.

DP Interface
Interface for direct connection of distributed I/Os to the CPU.