Configuration
3.4 Tuning Set Up Group
Introduction
Tuning consists of establishing the appropriate values for the tuning constants you are using so that your controller responds correctly to changes in process variable and setpoint. You can start with predetermined values but you will have to watch the system to see how to modify them. The Accutune feature automatically selects Gain, Rate, and Reset on demand.
ATTENTION
Because this group contains functions that have to do with security and lockout, we recommend that you configure this group last, after all other configuration data has been loaded.
Function Prompts
Table
| Function Prompt |
| Selection or Range of Setting |
| Parameter | ||||
| Lower Display |
| Upper Display |
| Definition | ||||
| English | Numeric |
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| English |
| Numeric |
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| Code |
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| Code |
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| PB or GAIN | 101 |
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| PB = 0.1 to 1000 % |
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| PROPORTIONAL BAND (simplex) is the | |
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| percent of the range of the measured | ||||
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| Gain = 0.01 to |
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| variable for which a proportional controller | |
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| 1000 |
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| will produce a 100 % change in its output. | ||
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| GAIN is the ratio of output change (%) over |
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| the measured variable change (%) that |
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| caused it. |
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| 100% | |
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| G = PB% |
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| where PB is the proportional band (in %) |
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| If the PB is 20 %, then the Gain is 5. And, at |
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| those settings, a 3 % change in the error |
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| signal |
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| the controller's output due to proportional |
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| action. If the Gain is 2, then the PB is 50 %. |
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| Also defined as "HEAT" Gain on Duplex |
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| models for variations of Heat/Cool |
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| applications. |
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| The selection of Proportional Band or Gain is |
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| made in the CONTROL parameter group |
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| under prompt PBorGAIN. |
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| RATE T | 102 |
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| 0.00 to 10.00 |
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| RATE action, in minutes, affects the | |
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| controller's output whenever the deviation is | ||||
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| minutes |
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| changing; and affects it more when the | ||
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| 0.08 or less = OFF |
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| deviation is changing faster. | ||
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4/07 | UDC2500 Universal Digital Controller Product Manual | 35 |
