IM 01C25R03-01E
A-34
APPENDIX 3. INPUT SELECTOR (IS) BLOCK
A3.6 Application Example
The following describes the temperature control system of a fixed bed-type reactor. In this case, there are instances
where the point showing the maximum temperature changes due to catalytic deterioration, raw material flow, etc.
Therefore, a large number of measurement points are provided, and the maximum value obtained among these
measurement points is input to the controller to control reactor temperature.
FA0310.EPS
IS
PID
AI3
AI1
AI2
AI4
AO
Refrigerant
Raw material
Product
Catalytic reactor
Figure A3.10 Temperature Control System of a Fixed Bed-type Reactor
IS
IN_1 4
OUT
PID
BKCAL_IN
OUT
IN
AO
CAS_IN
BKCAL_OUT
AI1
OUT
AI1
OUT
AI
OUT
AI1
OUT
AI1 AI4
FA0311.EPS
Figure A3.11 Example of Scheduling
AI1 : Temperature 1, AI2: Temperature 2, AI3: Temperature 3, AI4: Temperature 4
IS
: SELECT_TYPE = MAX
Basic operations and work sequence:
1. The IS block obtains values and status information from AI.
2. The block selects the AI information using the alternatives.
3. The block displays and outputs the information selected by SELECTED.
