Ads
related to: plc timer functions free
Search results
Results from the WOW.Com Content Network
Watchdog timers may have either fixed or programmable time intervals. Some watchdog timers allow the time interval to be programmed by selecting from among a few selectable, discrete values. In others, the interval can be programmed to arbitrary values. Typically, watchdog time intervals range from ten milliseconds to a minute or more.
A programmable logic controller (PLC) or programmable controller is an industrial computer that has been ruggedized and adapted for the control of manufacturing processes, such as assembly lines, machines, robotic devices, or any activity that requires high reliability, ease of programming, and process fault diagnosis.
IEC 61131-3 is the third part (of 10) of the international standard IEC 61131 for programmable logic controllers.It was first published in December 1993 [1] by the IEC; the current (third) edition was published in February 2013.
They include timers, arithmetic operators and comparisons, table lookups, text processing, PID control, and filtering functions. More powerful PLCs can operate on a group of internal memory locations and execute an operation on a range of addresses, for example, to simulate a physical sequential drum controller or a finite-state machine .
A feedback control loop is directly controlled by the RTU or PLC, but the SCADA software monitors the overall performance of the loop. For example, a PLC may control the flow of cooling water through part of an industrial process to a set point level, but the SCADA system software will allow operators to change the set points for the flow.
Siemens SIMATIC S7-300 PLC CPU with three I/O modules attached. As with other programmable logic controllers, SIMATIC devices are intended to separate the control of a machine from the machine's direct operation, in a more lightweight and versatile manner than controls hard-wired for a specific machine. Early SIMATIC devices were transistor ...
Ads
related to: plc timer functions free