Description
SE4050E1C0 New Emerson Ovation DCS Card
thereby controlling external devices or circuits.
Just as every unit in memory has an address, every device in the system also has an address, and the device controller must be able to recognize the address of each device it controls. In addition, in order for the CPU to write (or read) data to (or from) registers, these registers should have unique addresses.
Basic functions of DMA controller
(1) There is a pair of communication signal lines between DMAC and external devices – the DMA request signal DREQ from the external device and the DMA response signal DACK sent by DMAC to the external device;
(2) After receiving DREQ, DMAC also has a pair of communication signal lines with CPU – DMAC sends a bus request signal (HOLD or BUSRQ) to CPU, and CPU sends a bus response signal (HLDA or BUSAK) to DMAC after the current bus cycle ends. DMAC takes over control of the bus and enters DMA operation mode;
(3) Capable of sending address information, addressing memory, and modifying address pointers, DMAC must have an address register that can automatically add or subtract 1 internally;
(4) Can determine the number of bytes to be transferred and determine whether the DMA transfer has ended. There must be a word count register inside DMA that can automatically subtract 1, and a termination count signal is generated when the count ends;
(5) Can send DMA end signal, release the bus, and restore bus control to the CPU;
(6) Capable of issuing read and write control signals, including memory access signals and I/O access signals.
responsible for processing signals from on-site sensors or driving actuator actions. For example, they may need to cooperate with devices such
as BANNER travel switch T30UIPB to receive their transmitted position signals; Or by controlling components such as Burkert solenoid valve 00131421, the on/off of fluid media can be precisely managed.
these modules integrate more complex logic processing capabilities. The core task of a pressure switch is to detect whether the pressure
has reached a preset threshold and output a switch signal. Its function is highly specific and fixed. And modules SE4050E1C0 and 1
C31219G01 have the ability to comprehensively judge multiple such switch signals and transmitter signals (such as transmitter 1066-P-HT-60),
and output complex control instructions according to internal logic.
