Second Set Point; Second Pid Set - Brainchild PR10 User Manual

10 D.O1.2: Disable both Output 1 and Output 2 by clearing MV1 and MV2 values as soon
as the event input is activated.
Note: When any of D.O1, D.O2 or D.O1.2 is selected for EIFN, the output 1 and/or
output 2 will revert to their normal conditions as soon as the event input is released.
11 LOCK: All parameters are locked to prevent from being changed.
12 SP2F Function: Define format of SP2 value. If SP2F in the setup menu is selected with
ACTU, the event input function will use SP2 value for its second set point. If SP2F is
selected with DEVI, the SP1 value will be added to SP2. The sum of SP1 and SP2
(SP1+SP2) will be used by the event input function for the second set point value. In
certain applications it is desirable to move second set point value with respect to set
point 1 value. The DEVI function for SP2 provides a convenient way in this case.

5.2.4.14 Second Set Point

In certain applications it is desirable to change the set point automatically without the need to
adjust the set point. You can apply a signal to event input terminals. The signal applied to event input may
come from a Timer, a PLC, and an Alarm Relay, a Manual switch or other devices. Select SP2 for EIFN
which is contained in setup menu. This is available only with the case that SP1.2, MIN.R or HR.R is used for
SPMD, where MIN.R and HR.R are used for the ramping function.
Application 1: A process is required to be heated at a higher temperature as soon as its pressure exceeds
a certain limit. Set SPMD=SP1.2, EIFN=SP2 (or SP .P2 if the second PID is required for the higher
temperature too).The pressure gauge is switched ON as it senses a higher pressure. Connect the output
contacts of the pressure gauge to the event input. SP1 is set with a normal temperature and SP2 is set with
a higher temperature. Choose ACTU for SP2F.
Application 2: An oven is required to be heated at 300°C from 8.00 AM to 6.00 PM After 6.00 PM it is
desirable to be maintained at 80°C. Use a programmable 24 hours cycle timer for this purpose. The timer
output is used to control event input. Set SPMD=SP1.2, and EIFN=SP2 (or SP .P2 if the second PID is
required to be used for the second set point).SP1 is set with 300°C and SP2 is set with 80°C. Choose
ACTU for SP2F. After 6.00 PM the timer output is closed. The event input function will select SP2 (=80°C)
to control the process.

5.2.4.15 Second PID Set

In certain applications the process characteristics is strongly related to its process value. The
Process Control Card provides two set of PID values. When the process is changed to different set point,
the PID values can be switched to another set to achieve an optimum condition.
The optimal PID values for a process may vary with its process value and set point. Hence if a
process is used for a wide range of set point, dual PID values are necessary to optimize the control
performance. If the first PID set is selected (event input is not applied) during auto-tuning procedure, the
PID values will be stored in PB1, TI1 and TD1. Similarly, if the second PID set is selected (event input is
applied while PID2 or SP.P2 is selected for EIFN) during auto-tuning, the PID values will be stored in PB2,
TI2 and TD2 as soon as auto-tuning is completed.
Application 1: Programmed by Set Point
Choose SP.P2 for EIFN then both set point and PID values will be switched to another set
simultaneously. The signal applied to event input may come from a Timer, a PLC, and an Alarm Relay, a
Manual Switch or other devices.
Application 2: Programmed by Process Value
If the process value exceeds a certain limit, 500°C for example, it is desirable to use another
PID values to optimize the control performance. The user can use a process high alarm to detect the limit of
the process value. Choose PV1H for A1FN, A1MD selects NORM, adjust A1SP to be equal to 500° C, and
choose PID2 for EIFN. If the temperature is higher than 500°C, then alarm 1 is activated. The alarm 1
output is connected to event input; the PID values will change from PB1, TI1 and TD1 to PB2, TI2 and TD2.
Page 146 of 479