Honeywell DCP551 Mark ΙΙ User Manual page 101

• Auto-tuning always calculates the excess time and limit sensitivity of thread for two
limit cycles and calculates PID values using characteristics equations, then automati-
cally writes the results.
C21
• The setup data
auto-tuning.
C21
setting of 1, 3 or 5 causes the lower output limit to be determined by variable
PA09
parameter and the upper output limit to be determined by
C21
setting of 2 or 4, lower output limit is off and the upper output limit is on.
• The point at which output reverses (lower limit ⇔ upper limit) during auto-tuning is
determined from the SP and PV values at AT startup as follows.
Starting
PV
When PV > SP
2/3
1/3
SP
1/3
2/3
When PV < SP
AT start Normal end
• Auto-tuning performed using a variable parameter
auto-tuning to be performed on SP, PID parameters
PV
tP-A7
tP-A6
tP-A5
tP-A4
tP-A3
tP-A2
tP-A1
• Auto-tuning can be started by the AT key, external switch input and by transmission.
The AT LED flashes during auto-tuning.
• Auto-tuning terminates without writing PID constants and the AT LED goes off
when any of the following conditions occur.
• Operation is terminated by pressing of the AT key.
• Operation is terminated by an external switch input.
• Operation is terminated by transmission.
• Mode change occurs. (When the MANUAL mode is invoked; the READY mode
is invoked by setting
to 3 or 4.)
• When PV goes outside the range.
setting changes the upper and lower output limit used during
Running SP = PV
PV
SP
Time
AT start
PA08
to 1 or 2, the RUN mode is invoked by setting
Chapter 6. OPERATION
PA10
.
Time
Normal end
PA08
setting of 3 or 4 causes
tP-A1 tP-A7
to , in order.
Time
PA08
6-13