Trimec rt11 - Rate Conversion Factor; Non Linearity Correction ( NLC) Linearisation; Low Frequency Cut-Off ( Refer Clause 2.4 Page 5 ); PROGRAM PARAMETERS ( Models RT11& RT12 )

12 Programming
4. PROGRAM PARAMETERS ( models RT11 & 12 )
4.1 PIN No. Program Protection
Any user defined PIN number other than 0000 will engage the program protection feature,
failure to input the correct PIN number will deny the ability to change any of the program
parameters but will allow the user to step through and view the existing program parameters.
Only one PIN number may be set but this can be changed at any time after gaining access
through PIN entry. A second back up PIN number is installed at the factory should the
programmed PIN be lost or forgotten. ( refer bottom of page 17 for the back up PIN No. )
4.2 Resetting Accumulated Total
Resetting the accumulated total can only be done at level 2 (L2) in the program mode.
4.3 Engineering Units ( refer clause 1.4 )
Select from available Engineering units to right of the display. No eng. units denote NIL set.
4.4 K-factor (scale factor)
Enter K-factor starting with the most significant number, up to 7 whole numbers & 3 decimal
numbers can be entered. Trailing decimal numbers move into view as digits to the right are
progressively selected, any significant digits which may move from view remain functional.
4.5 Rate conversion factor
A rate conversion feature is available & is explained at level 6 in the program chart (page 14).
4.6 Rate dampening
Dampening is available to smooth out fluctuating flow input signals in order to provide a
stable rate
display & analog output. Most input signal are reasonably stable and need only a
low setting value of 40 to 70 ( see response graph on page 19 ).
4.7 Low frequency cut-off This feature is explained in clause 2.4 ( page 5 ).
4.8 Pulse Outputs ( Instrument must be externally powered as per page 10 )
The pulse output is link selectable as a scaleable pulse or non-scaled repeater pulse & NPN
(current sinking) or PNP (current sourcing) style pulse capable of switching up to 1 amp.
Pulse scaling, when selected, is set as the number of litres / gallons etc. per output pulse
Eg. 0.1 litres/pulse, 10 litres/pulse, 100 gallons/pulse. Range is 0.1 - 9999.9 Eng.unit/pulse.
The pulse width (pulse duration 1:1) automatically adjusts to the output frequency defaulting
to a maximum pulse width of 300 milliseconds at frequencies below 1.66hz. To calculate
pulse width at higher frequencies use: 1000 ÷ (hz x 2) = pulse width in milliseconds.
4.9 Non Linearity Correction ( NLC ) - Linearisation
Linearisation enables the instrument to correct for known inaccuracies in a flowmeter thereby
improving the overall accuracy and in many cases increasing the effective flow range
(turndown) of the flowmeter. Refer to program level L12, page 15 for setting NLC points.
NLC can be used without external power however, battery life is reduced according to usage.
Note: The RT defaults out of the program mode if no programming entries are made after 4 minutes.
Installation 9
3.2 Flowmeter connections ( powered sensors )
4. Hall effect ( 5~24Vdc open collector )
DIP SW2 (pull up) is on
Hall effect
Reg. Vdc
_
+
Vdc supply
- 0V ground
+ Signal out
6
5
4
3
2
1
7
+8~24Vdc in
Pulse output
-0V (ground)
Flow
Input A
-
4~20mA output
-
0V (ground)
not used
+4~20mA output
Low flow alarm
8
9
10
11
12
13
14
High flow alarm
not used
Flow
Input B
3
2
1
O
N
3
2
1
O
N
Ground screen
at terminal 5
5. Namur ( inductive proximity switch )
NOTE :
Limit supply to 8.5Vdc
through an approved barrier for
intrinsically safe NAMUR proximities
DIP SW3 (pull down) is
on
NAMUR
Inductive Proximity
-
+
Reg. Vdc
_
+
6
5
4
3
2
1
7
+8~24Vdc in
Pulse output
-0V (ground)
Flow
Input A
-
4~20mA output
-
0V (ground)
not used
+4~20mA output
Low flow alarm
8
9
10
11
12
13
14
High flow alarm
not used
Flow
Input B
3
2
1
O
N
3
2
1
O
N
Ground screen
at terminal 5
6. Current modulated pulse ( 4mA mark & 20mA space )
NOTE : Position a 100Ω, ¼W
Resistor across terminals 3 & 5
DIP switches off
-
+
Coil with pre-amp
current modulated
B
A
Reg.Vdc
_
+
6
5
4
3
2
1
7
+8~24Vdc in
Pulse output
-0V (ground)
Flow
Input A
-
4~20mA output
-
0V (ground)
not used
+4~20mA output
Low flow alarm
8
9
10
11
12
13
14
High flow alarm
not used
Flow
Input B
3
2
1
O
N
3
2
1
O
N
Ground screen
at terminal 5