Micromod Micro-DCI: 53SL6000 Single Loop Controller - Manual (Page 102)

control element, the period should be set to
match the end-to-end travel time of the ele-
ment. To operate the digital outputs in a time
proportioning manner, much shorter cycle
times are required. Because each cycle period
is divided into 0.05 second pieces, the resolu-
tion of the output is determined by the length of
the cycle period.
For example: If dcP is 10 seconds, then the
period will contain 200 pieces (10/0.05 = 200),
each being 0.5% of the 10 second period. If
the controller output (OUT) value is 27.65 (%)
at the start of the period, then the VuP logic will
remain a "1" for 2.8 seconds (27.65% rounded
to the closest 0.5% = 28.1 or 28%; 0.28 x 10
seconds = 2.8 seconds). 2.8 seconds is
equivalent to 56 pieces. The cycle period will
be a "0" for the remainder of the period, which
is 7.2 seconds (144 pieces). The dcp value
affects the discrete output pulse repitition fre-
quency. A dcp of 0 turns off VuP and Vdn.
• Enter a minimum manual time in conF-cn.1-
MMt. This value designates the mode of man-
ual operation associated with the VuP and Vdn
logic signals. When MMt = 0, VuP and Vdn are
always a pulse width modulated (PWM) repre-
sentation of the control OUT signal. The PWM
period is determined by the dcP parameter.
When MMt = non-zero, VuP and Vdn are PWM
representations in automatic operation; how-
ever, in manual operation, they are only active
when either the of the output push buttons is
pressed. A non-zero value entered for MMt
represents in percent the minimum duty cycle
period the logic values VuP and Vdn will be a 1
whenever the output push buttons are momen-
tarily depressed or when a networked device
generates an associated push button opera-
tion.
Non-zero operation:
OUT
PB
VuP
dcP
Sec.
0 1 2 3 4 25 26 27 28 29 30
dcP = 30 seconds
MMt (MMt = 5% dcP)
• Enter a value into conF-cn.1-Pb between 0.02
and 1000. The %Pb is determined from the
speed factor, which is calculated as follows:
Speed Fact or =



% input deviation
% output dut y cy cl e



X 100
or Speed Factor = % deviation required for
maximum motor speed.
Because the controller operates as a devia-
tion-to-duty cycle converter and the motorized
control valve provides the integral action, the
total integral gain depends not only on the con-
troller Pb setting but also on the speed of the
valve. Integral gain is expressed as follows:
Integral Gain
= 


Speed Factor of Controller
full stroke travel t i m e of valve in seconds



•
Enter a control zone value to reduce motor
hunting in conF-cn.1-cZ. The peak-to-peak
value of noise or fluctuation of the process
signal must be smaller than the control zone
for stable operation. A control zone as wide as
possible should be entered to extend the serv-
ice life of the motorized valve operator.
• Select the desired controller output-to-process
variable relationship (dir/rEV) with conF-cn.1-
rSW.
• Scale the slide wire analog input 2 signal with
conF-cn.2-(SPAn, ZEro) as follows:
The limit switches in the valve operator should
be properly adjusted. Refer to the appropriate
manufacturer’s instructions for details. In
manual operation, depress and hold the con-
troller’s increase output or decrease output
push button. Check that the final control ele-
ment operates in the proper direction and that
the slide wire valve indicator (yellow dro)
moves in the proper direction (0% represents
fully closed, 100% represents fully open). En-
sure the valve indicator tracks the valve posi-
tion.
Drive the valve fully closed and adjust the Ai.2
module conF-cn.2-ZEro parameter for 0% me-
ter position.
Drive the valve fully open and adjust the Ai.2
module conF-cn.2-SPAn parameter for 100%
meter position.
Section 8. Eight Control Strategies 53SL6000 Instruction Manual
8-15