Trimec rt11 - Flowmeter Connections - Unpowered Sensors

8 Installation
3.2 Flowmeter connections ( unpowered sensors )
Programming 13
4.10 Presetting battery power levels
When the instrument is operated under battery power only a special “Power Mode” program
option will appear at level 13 within the programming routine. A choice of three battery power
modes enable maximisation of the battery life according to operational requirements:
Ultra Power Save:
Typically selected if reading the register infrequently. The display scrolls a
Prompt “PRESS ANY KEY”, when a key is pressed display wakes up for
4 minutes then returns to sleep mode* greatly extending the battery life.
Standby : Display becomes active whenever a key is pressed or product flows
through the flowmeter. Display returns to sleep mode* after 4 minutes of
no flow input or key actions, prompt then returns to “PRESS ANY KEY”.
Continuous: Display is active at all times resulting in reduced battery life. Display
reverts from Rate to Total after 4 minutes to reduce battery draw.
* In sleep mode (and programming mode) flow is always continually totalised.
5. ADDITIONAL PROGRAM PARAMETERS ( model RT12 )
5.1 Analog Output
The loop powered 4~20mA output can be spanned anywhere within the flow meter range.
Testing the current loop is available during programming when 4mA will output at
programming level L15 and 20mA will output at level L16 (page 16).
5.2 Flow Alarms
Two flow alarm FET (transistor) outputs may be programmed for Low & High flow alarms.
5.3 Flow Alarm Deadband
Alarms are NPN/PNP link selectable. An adjustable deadband (reset differential) provides
a trip buffer zone about the set point in order to overcome alarm “chattering” when the flow
rate is fluctuating close to the alarm set point.
Deadband is entered as % of each set point value (refer to page 16 for an example).
5.4 Dual Flow Inputs (see also page 20 for a fuller description)
When externally powered the RT12 accepts inputs from two flowmeters (input A & input B),
a separate scaling factor is entered for the second flow input, the instrument is then
programmed for one of the dual input functions of A+B, A-B or A÷B (ratio).
A+B Both inputs are added and displayed as one for Rate & Totals.
A-B Input B is subtracted from input A & the difference is displayed for both Rate & Totals.
A÷B Totalises A & B separately & Rate is a function of A÷B to give instantaneous ratio.
Note : - When using A & B inputs the functions of Scaled Pulse output, Alarm set points
and the Analog output are relevant to resultant computation between A & B.
- The analog output of function A÷B can be used as an input for ratio control.
1. Reed switch ( 200hz max.)
DIP
switch 1
(debounce)
&
Switch 2 (pull up) are on
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 -0V (5)
3. Coil ( Turbine & paddle style flowmeters )
All DIP switches off (position switch 1
ON if unit is effected by line noise)
use twisted pairs
6
5
4
3
2
1
7
+8~24Vdc in
Pulse output
-0V (ground)
Flow
Input A
-4~20mA output
-
0V (ground)
n
ot 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
2. Pulse wire
All
DIP swit
hes off
S
N
0.1 ~ 2 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
-
0V (5)
Switch 1 : ON engages 0.01µf capacitor to suppress reed switch bounce
Switch 2 : ON engages 1 meg Ω pull up resister
Switch 3 :
ON engages 820
Ω
pull down resister
3
2
1
O
N
Flow input A & B switch functions
Terminals 1, 2 & 5 replicate terminals 3, 4 & 5 for dual flow inputs
3
2
1
O
N
A
B
Switch 1 : ON engages 0.01µf capacitor to suppress reed switch bounce