ABB DSQC604 3HAC12928-1 Output Latch

DSQC604 3HAC12928-1 also corresponds to the output mapping area in the PLC memory. An output latch also has a memory bit (bit) corresponding to it, which is called an output relay, or output coil. By running the system program, the state of the output relay is mapped to the output latch. This mapping is also called output refresh. Output refreshing is also achieved primarily by running a system program. Thus, all the user has to program is the conversion of the input mapping area to the output mapping area in the memory, especially how to convert the timing of the inputs to the timing of the outputs. This is a data and logic processing problem. Since PLC has a powerful instruction system, it is entirely possible and relatively easy to write a programme that meets this requirement.

DSQC604 3HAC12928-1 in industrial plc control system, remote i/o is a kind of high-speed local area network, in fact, it is a bus way to connect the input/output devices and the central controller (cpu), so as to realise the remote control of input/output devices of a kind of solution. There are a variety of bus methods, the major companies to develop products have their own characteristics, for example, some companies use profibus-dp fieldbus, the communication medium for the shielded twisted pair, some companies use 75ω coaxial cable and catv media technology. Although the application of the media are different, but the requirements of the system is basically the same

DSQC604 3HAC12928-1 are as follows:

(1) ensure the consistency of data transmission

Ensure accurate and high-speed data transmission is the basic requirement for remote i/o. Most of the data in the rio processor (in the front end of the plc) and rio adapter (in the remote sub-station) between the transmission, for i/o remote sub-station is less than 1ms.

(2) Predictable speed with strict control of time requirements