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3.11
Failure Transfer
The controller will enter failure mode if one of the following conditions occurs.
1.
An “SBER” error occurs due to an input sensor break, an input current below 1mA for 4-20mA, or an
input voltage below 0.25V for 1-5V.
2.
An ADER error occurs due to the A-D converter of the controller fails.
Output 1 and Output 2 will perform the failure transfer (O1.ft & O2.ft) function if the controller enters
failure mode.
3.11.1
Output 1 Failure Transfer
If Output 1 Failure Transfer is activated, it will function as follows:
1.
If output 1 is configured as proportional control (PB
≠
0), and BPLS is selected for O1FT, then output 1
will perform a Bumpless transfer. After that, the previous average value of MV1 will be used for
controlling output 1.
2.
If output 1 is configured as proportional control (PB
≠
0), and a value of 0 to 100.0 % is set for O1FT,
then output 1 will perform failure transfer. After that the value of O1FT will be used for controlling
output 1.
3.
If output 1 is configured as ON-OFF control (PB=0), then output 1 will transfer to an off state if OFF is
set for O1FT, and transfer to on state if ON is set for O1FT.
3.11.2
Output 2 Failure Transfer
If Output 2 Failure Transfer is activated, it will function as follows:
1.
If OUT2 is configured as COOL, and BPLS is selected for O2FT, then output 2 will perform a
Bumpless transfer. After that, the previous average value of MV2 will be used for controlling output 2
2.
If OUT2 is configured as COOL, and a value of 0 to 100.0 % is set for O2FT, then output 2 will
perform a failure transfer. After that the value of O2FT will be used for controlling output 2.
3.
If OUT2 is configured as an alarm function, and OFF is set for O2FT, then output 2 will transfer to an
off state, otherwise, output 2 will transfer to an on state if ON is set for O2FT.
3.11.3
Alarm Failure Transfer
An alarm failure transfer is activated as the controller enters failure mode. After that, the alarm output will
transfer to the ON or OFF depending on the set value of A1FT, A2FT, A3FT, and A4FT.
3.12
Auto-Tuning
The Auto-Tuning process will be performed using the set point (SP1). The process will oscillate around
the set point during the tuning process. Set a set point to a lower value if overshooting beyond the normal
process value will cause damage. It is usually best to perform Auto-Tuning at the Set point the machine is
expected to be operated at, with the process running normally (i.e. material in the oven, etc.)
Auto-Tuning is generally applied in the following cases:
v
Initial setup for a new process
v
The set point is changed substantially from the previous Set point when Auto-Tuning was performed.
v
The control result is unsatisfactory
