In addition, the parameters of dead time, process range, and time constant also determine saturation time, interval (period), and minimum tune band. These parameters remain constant and are unchanged by PRAC+ adaptive tuning. Therefore, make sure to select the correct process ID for the mechanical system.
Parameter |
ZN-T (°F) |
DA-T (°F) |
---|---|---|
Dead Time |
30 |
20 |
Process Range |
27 |
54 |
Time Constant |
900 |
200 |
Saturation Time |
300 |
60 |
Interval (Period) |
60 |
12 |
Minimum Tune Band (PR x 0.04) |
1.08 |
2.16 |
At Metasys Release 5.1, several process IDs were changed to be much more aggressive. If you transfer an application to the computer, upgrade, and then transfer the application to the device, the control continues with the tuning parameters at the time of the transfer to computer. If you use an application that was created in CCT/PCT and still has the default tuning parameters, and you upgrade to CCT/PCT 5.1 or later, the control uses the more aggressive tuning parameters introduced at Release 5.1. See Appendix: Process IDs for the initial values of process IDs across recent Metasys releases.