I am working on a project to replace the existing control system on a mechanical shock tester. I would like to capture a short burst analog waveform for about 2 seconds. I am considering using a PLC. There are several factors. Has anyone seen this type of application on a plc.
Background: The machine applies a load to a shock and the releases the load and then captures the feedback from the shock, Torque vs Speed. The waveform is approx 2 seconds. The machine is controlled by an old GE series 1 PLC. The analog values are DC (Torque 0-10volts) using a Wheatstone bridge load cell and the Speed is using a Tachometer (DC millivolts). These signals are captured using a Daytronic analog rack w/ several modules for upper and lower limits. This waveform is then sent to a printer for graphing.
Obviously, there are two things to consider: 1. PLC scan rate. 2. Filtering of the analog card. Are there others? I am assuming approx
200-400 samples per 1/2 second. That is scan times of less than 2ms. One of these test are run every 30 minutes. I figure the best way to accomplish this in the logic is to write the two analog values to a sequence of registers and after the two seconds send the complete array of register out to a scada or excel sheet.
Any ideas or thoughts would be greatly appreciated.