Real time clock

Real-time clocks (RTCs). Real-time systems are required to respond to events, as they occur, in a timely manner. This is especially crucial in process control systems where control actions applied at the wrong time may amplify process deviations or destabilize the processes. The nodes in the systems are interrupted periodically by the real-time clocks to maintain the ac tual elapsed times. 

With the Kalousek computer polarograph, a programmable real-time clock (with rates up to 1 MHz) and an operational amplifier were used, and the computer had to perform the following functions ... 

Real-time clocking of abstraction reactions was first performed on the I-H/CO2 system for the dynamics on the ground-state PES [5] ... 

Real-Time Clock. The real-time clock produces a program interrupt at one of four frequencies, independent of processor timing. The realtime clock is used in GPC work to implement sampling at user specified intervals. 

SET REAL-TIME CLOCK TO CURRENT TIME THEN PUSH "GO"... 

To calculate shear stress, shear rate and melt viscosity, the melt pressure and piston velocity must be monitored. The former is measured using a 0 to 20,000 psi pressure transducer mounted in the rheometer barrel just above the capillary. A linear potentiometer is used to monitor piston position during the test. Utilizing the piston displacement data and the HP real time clock, the piston velocity is calculated. 

The HP 3052A data acquisition system consists of a 9825A calculator with a real time clock, a multichannel scanner, a high speed digital volt meter and a printer/plotter for display purposes. The system software consists of a monitoring program and an analysis program written in HPL. 

Operator interaction with the data acquisition system occurs in the manner shown in Figure 1. The user specifies a time interval, usually several seconds, over which the computer will calculate piston velocity and melt pressure. With the system described above the time interval must be on the whole second since this is the resolution of the real time clock. 

Real-time clock Every digital computer used for process control must have a real-time clock. This is the device that keeps track of the real world s time and allows the computer to schedule its functions at time intervals in coordination with the various needs of the real world. Thus it is the real-time clock that determines when the computer should take data from measuring sensors or change the values of manipulated variables. 

What is the real-time clock needed for How does it function Why is it very difficult to use a computer for process control without a real-time clock Do you have any suggestions on how you can count time elapsed without a real-time clock ... 

Random access memory (RAM), 355 Ratio control, 427-29 references, 446-47 Reaction curve, 310-11 in controller tuning, 311-15 Reaction equilibria, 56 Reaction kinetics, 55, 61-62 Reactors (see Chemical reactors) Read-only memory (ROM), 555 Real-time clock, 554 Reboiler, 71-73... 

M8043(DLV11J) 1 4 CHAN. SERIAL INT. 1 TCO-50 REAL TIME CLOCK 1 1... 

QuadMode Air Sampling Technology Selectable Automatic Fault Recovery Standard Temperature Pressure Correction Superior Design Comfort Real-time Clock with Data-logging... 

Real-time Clock with Data-logging... 

With a real-time clock the average number of counts recorded in a real time t is defined by Eqs. (4.97) and (4.100), depending on whether the deadtime is nonpar-alyzable or paralyzable. The expected number of measured counts nm is related to the expected number of photons at the detector nt by... 

With the simple real-time clock the measured counts must always be corrected for deadtime losses. The true number of counts nt is calculated from the measured counts using Eq. (4.131) or (4.132) and the known value of the deadtime td. The variance in the calculated counts nt caused by can be computed to be... 

Drifts in clock frequency on the livetime clock or elapsed real time clock due to temperature or ac line frequency changes... 

Real-time clocks. Process control systems must respond to events in a timely manner and should have the capability of real-time control. 

Real- time clock Work and program memories... 

Real-Time Clocking of Bimolecular Reactions Applications to H + CO2. 

---