ControlMaster CM30, CM50 and CMF310
Universal process controllers,
1
/
4
,
1
/
2
DIN and fieldmount
6 Basic Level
32
IM/CM/ED–EN Rev. X
…Basic / …Loop 1 Mot Valve
Calculation for Control Pulses (Boundless Control)
The following calculations are for guidance when setting Deadband, proportional and integral values and are
applicable only to Boundless control.
The Deadband on the ControlMaster is set in engineering units. To calculate the integral values, the engineering units
must first be converted to a % using the following calculation:
The calculated % Deadband can now be used in the following integral action calculations:
Minimum 'ON' time of integral action pulses (for a fixed control deviation)
Minimum (approximate) time between integral action pulses (for a fixed control deviation)
Duration of the proportional step
% Control Deviation
% Deadband = Deadband (eng units) x 100
Eng Hi - Eng Lo
= Travel Time x % Deadband (in seconds)
% Proportional Band
= 2 x (% Control Deviation) x Travel Time in seconds
(% Proportional Band)
= Integral Action Time x % Deadband (in seconds)
2 x Control Deviation
= Setpoint - Process Variable x 100%
Eng Hi - Eng Lo