FCS, DCS, PLC control system Characteristics and differences

90 's of the last century to the practicality of the fieldbus control system is a rapid momentum of rapid development, is currently the world's most modern control systems. Fieldbus control system is a focus in automation technology, is growing by domestic and foreign manufacturers of automation equipment and user attention. The appearance of fieldbus … Continue reading FCS, DCS, PLC control system Characteristics and differences

S7-300/400 plc the difference between FC and FB

1. FB har en baggrund luns, FC har ikke en baggrund luns. Dette er den mest afgørende forskel.Baggrund datablokke styres hver af en privat butik, som om kontrolleret personlig værdiboks i banken. Temp er mere end FB, FC blev opkrævet med en fælles dataområde, ligesom opslagstavler, alle kan underskrive en bekendtgørelse, sendt meddelelser vil blive … Continue reading S7-300/400 plc the difference between FC and FB

S7-300 PLC arbitrary bit (greater than 32) rotate left

Greater than 32 bits Arbitrary bit Rotate Left an idea. In 64 + N bits, for example,First, each Rotate Left Double Word 1, respectively,Double the maximum displacement of each word to its lowest position. Then each of the least significant bit double word is transmitted to the double word to its left is the least significant … Continue reading S7-300 PLC arbitrary bit (greater than 32) rotate left

S7-200PLC the PPI protocol

Hardware and software methods by listening, analyzing internal PLC inherent PPI protocol, then the host computer using VB programming, follow the PPI protocol, data reading and writing PLC, man-machine operation tasks. This communication method, compared with the general freedom of communication protocols, omitted through the PLC programming, just the preparation of the PC communication program … Continue reading S7-200PLC the PPI protocol

PLC oscillation circuit Ladder Logic

Oscillation circuit analysisX0 turns T1 coil excited,4s after T1 delay normally open contact closure,While T2, Y1 coil excited, Y1 output.After T2 coil excited 2s produce a series of actions in the following order (note the timing chart corresponding analysis). ①T2 normally closed contacts disconnect② make T1 energized coil,③ T1 coil power loss and enable T1 normally … Continue reading PLC oscillation circuit Ladder Logic