Siemens S7-400 Timer T, Toggle switch, Total Current, Ungrounded, Update interrupt, User Memory

Glossary

Timer (T)

Timers are an area in the system memory of the CPU. The contents of these timers are updated by the operating system asynchronously to the user program. You can use STEP 7 instructions to define the exact function of the timer (for example, on-delay timer) and start processing it (Start).

Toggle switch

The mode selector is a toggle switch which can be used to set the CPU from RUN to STOP or reset CPU memory.

Total Current

Sum of currents of all output channels of a digital output module.

U

Ungrounded

Without galvanic connection to ground.

Update interrupt

An update inbterrupt can be generated by a DPV1 slave.

The DPV1 responds with a call of OB56. For detailed information on OB56, refer to the “System Software for S7-300/S7-400 System and Standard Functions” reference manual.

User Memory

The user memory contains logic blocks and data blocks of the user program. The user memory can either be intergrated in the CPU or can be plugged in on memory card or memory submodules. In general, however, the user program is executed from the work memory (RAM) of the CPU.

User Program

With SIMATIC a difference is made between the operating system of the CPU and user programs. The latter are generated by means of the STEP 7 programming software in the possible programming languages (Ladder Logic, Statement List, Function Block Diagram) and are stored in logic blocks. Data are stored in data blocks.

Automation System S7-400 Hardware and Installation A5E00850741-01

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