Siemens OCM III Instruction Manual
Instruction Manual November 2005
open channel
OCM III
Safety Guidelines: Warning notices must be observed to ensure personal safety as well as that of
others, and to protect the product and the connected equipment. These warning notices are
accompanied by a clarification of the level of caution to be observed.
Qualified Personnel: This device/system may only be set up and operated in conjunction with this
manual. Qualified personnel are only authorized to install and operate this equipment in accordance with
established safety practices and standards.
Unit Repair and Excluded Liability:
• The user is responsible for all changes and repairs made to the device by the user or the user’s
agent.
• All new components are to be provided by Siemens Milltronics Process Instruments Inc.
• Restrict repair to faulty components only.
• Do not reuse faulty components.
Warning: This product can only function properly and safely if it is correctly transported, stored,
installed, set up, operated, and maintained.
Note: Always use product in accordance with specifications.
Copyright Siemens Milltronics Process
Disclaimer of Liability
Instruments Inc. 2005. All Rights Reserved
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instrumentation described, variations
remain possible. Thus we cannot
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improvement.
Technical data subject to change.
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© Siemens Milltronics Process Instruments Inc. 2005
TABLE OF CONTENTS
TITLE PAGE
ABOUT THIS ...
About This Manual 7
About the OCM-3 7
SPECIFICATIONS 9
Programmer 10
Transducer 11
Temperature Sensor 11
Cabling 11
Communication Software 11
INSTALLATION
Installing the OCM-3 13
Outline and Mounting 13
OCM-3 Layout 14
System Diagram 15
Installing the Transducer 16
Installing the Temperature Sensor 16
mA Output 17
Relays 17
Synchronization 18
Power Connections 19
Installing the Memory Back-up Battery 20
Communicating Via Computer 20
Installing the Programmer 20
7ML19985AB01 OCM III 3
START UP
General 21
Keypad 21
Legend 22
Initial Start Up 22
Fundamental Checks 25
OPERATION
Memory 27
Security 27
Units 27
Flow Calculation 28
Display 28
Damping 29
Relays 30
mA Output 30
Fail-Safe 31
Flow rate and Totalizing 31
Logging 32
Blanking 34
Temperature 34
Time and Date 34
Emulation Mode 35
Reset 35
Flow Velocity Input 36
Auxiliary Head Input 36
DC Output 37
Diagnostic Aids 37
7ML19985AB01 OCM III 4
‘D’ PARAMETER LISTING 39
‘F’ PARAMET ER LI STING 41
‘P’ PARAMETER LISTING 43
‘U’ PARAMETERS FOR P3 PRIMARY ELEMENT 51
Simple Exponential Devices, P3 = 0 53
BS-3680 Rectangular Flume, P3 = 1 58
BS-3680 Round Nose Horizontal Crest Weir, P3 = 2 60
BS-3680 Trapezoidal Flume, P3 = 3 62
BS-3680 U - Flume, P3 = 4 64
BS-3680 Finite Crest Weir, P3 = 5 66
BS-3680 Thin Plate Rectangular Weir, P3 = 6 68
BS-3680 Thin Plate V-Notch Weir, P3 = 7 70
Rectangular Weir (Contracted), P3 = 8 72
Round Pipe, P3 = 9 74
Palmer-Bowlus Flume, P3 = 10 76
H - Flume, P3 = 11 78
Universal Head vs. Flow, P3 =12 80
Rectangular Area x Velocity, P3 = 13 82
Trapezoidal Area x Velocity, P3 =14 84
Modified Trapezoidal Area x Velocity, P3 = 15 86
U Channel Area x Velocity, P3 = 16 88
Circular Area x Velocity, P3 = 17 90
Gull-Wing Area x Velocity, P3 = 18 92
Egg-Shaped Area x Velocity, P3 =19 94
Universal Area x Velocity, P3 = 20 96
APPENDICES
Maintenance 99
Error Codes 100
Communications 101
7ML19985AB01 OCM III 5
7ML19985AB01 OCM III 6
ABOUT THIS ...
ABOUT THIS MANUAL
Although the OCM-3 is very ‘approachable’ due its dialogue capabilities and intuitive
operation, the user should be familiar with this manual. This manual provides the user
with the necessary information required to install, start up and operate the OCM-3.
As the OCM-3 prompts the user with specific messages in a step-by-step fashion
during programming, the Start Up section serves essentially to compliment the
OCM-3. Start Up provides the user with instructions on the use of the programmer
and an overview of the programming requirements.
The ‘D’, ‘F’, ‘P’ and ‘U’ parameters listed in the Parameters section provide a quick
reference of the available programming and display parameters and their options. The
‘U’ parameter listing also provides mathematical and graphical details as a reference
to assist the user in programming the OCM-3 to the primary element being used. The
user is urged to rely on the manufacturer’s specification for obtaining and identifying
the primary element to which the OCM-3 is being applied.
In short,
If you want to know about
the product About This . . .
getting started Installation
how it works Operation
Read
Specifications
Start Up
Parameters
Appendices
ABOUT THE OCM-3
The OCM-3 is to be used only in the manner
outlined in this instruction manual.
The Milltronics OCM-3, Open Channel Meter, is an electronic instrument designed to
measure flow in open channels. It is housed in a polycarbonate enclosure and comes
with a removable programmer. As a system, it is used in conjunction with a remote
ultrasonic transducer (or auxiliary head measurement device) and a temperature
sensor.
The OCM-3 transmits a pulse signal to the transducer which is then emitted as
ultrasonic pulses. The pulses echo off the water surface and are then sensed by the
transducer. The time for a pulse to echo back from the water surface is temperature
compensated and converted into a measurement of head.
7ML19985AB01 OCM III 7
The OCM-3 converts the head measurement into flow rate, but also provides a
velocity sensor input for applications where a flow velocity measurement is required to
perform the flow calculation. The flow rate is totalized and stored in a comprehensive
data log to provide detailed flow analysis.
Programming of the OCM-3 allows the operator to select the flow calculation specific
to the primary measuring device (flume, weir or pipe). Special emphasis has been
placed on providing the most accurate flow calculations possible. To this end, specific
routines have been written to comply with the British Standards Institute’s
Specifications BS-3680. These routines calculate correction factors taking into
account second order effects such as approach velocity and boundary layer. In the
event that flow measurement is not covered by one of the flow calculations provided,
the OCM-3 can be programmed for flow measurement using one of the universal
flow calculations.
The OCM-3 provides serial communication for remote programming, data log retrieval
and print out for devices such as computers, PLCs and printers. Milltronics provides a
standard utilities software package for OCM-3 programming, remote display and data
retrieval. However, the user is not limited to the software provided. The user can
develop his own software program to perform tasks suited to his specific nee ds.
The OCM-3 features:
✓ multi field illuminated LCD, for ‘Flow and Total’ and ‘Relay Status’ display
✓ 0 or 4 to 20 mA output
✓ three multipurpose relays, including remote totalization
✓ 1 to 24 months data log, subject to logging rate
✓ extensive serial communication, including RS-232
✓ removable infra-red programmer
✓ AC and DC (bi-current) operation.
7ML19985AB01 OCM III 8
SPECIFICATIONS
Power: » dc supply: » 9 to 30 V DC, 8 W max
» ac supply: » 100/115/200/230 V ac ± 15%, 50/60 Hz,
20 VA max
Environmental: » location » indoor /outdoor
» altitude: » 2000 m max
» ambient temperature » – 20 to 50 °C (–5 to 122 °F)
» relative humidity » suitable for outdoor (Type 4X/Nema 4X
» installation category » II
» pollution degree » 4
Memory
back-up: » 3 V lithium battery (NEDA 5003LC or equivalent)
» operating life 1 year
» ‘SuperCap’ capacitor for back-up
during battery replacement
Range: » 0.3 m min to 1.2 m max ( 1 to 4 ft)
and / or
IP65 enclosure)
0.6 m min to 3 m max (2 to 10 ft)
Resolution: » 0.2 mm (0.007")
Accuracy: » ±1 mm/m, calculated error less than 0.02%
Temperature
Compensation: » external sensor to compensate over
the operating range
Programming: » via supplied programmer and
communication link
Inputs: » velocity sensor and
auxiliary head » range: » 0 to 10 V dc
» resolution: » 2.7 mV
Outputs: » transducer drive: » 44 Khz, 400 Vpp pulses of 0.1 msec typical
duration at a 100 msec typical repetition rate.
» instrumentation: » range: 0-20 or 4-20 mA
7ML19985AB01 OCM III 9
» resolution: 5 uA
» maximum loading: 1 KΩ
» isolation: 300 V ac continuous
» relays: » 3 alarm/control relays
» 1 form ’C’ SPDT contact per relay, rated at
5 A at 250 V ac non-inductive or 30 V dc
» dc output: » +24 V dc
» 20 mA average to 200 mA at 1/10 duty
cycle max
Communication: » RS-232 or ± 20 mA bipolar current loop,300,
600, 1200, 2400, 4800, 9600 or 19200 baud
Data Logs: » variable rate on 1, 5, 15, 30 or 60 min or 24 hr
» 31 days minimum/2 years maximum
Display: » illuminated liquid crystal 5 x 7 dot matrix
display with 2 lines of 40 characters each
Enclosure: »Type 4X / NEMA 4X / IP65
» 209 mm W x 285 mm H x 92 mm D
(8.2" W x 11.2" H x 3.6" D)
» polycarbonate
Weight: » 2.3 Kg (5.1 lb)
Approvals: » CE *, FM, CSA
» MCERTS Class 1 open channel flow device with environment
operation limits at 35 °C (95 °F) at 93% relative humidity
SIRA MC 050058/01
PROGRAMMER
NRTL/C
Enclosure: » general purpose
Operating Temperature: » –20 to 50 °C (–5 to 122 °F)
7ML19985AB01 OCM III 10
» 67 mm W x 100 mm H x 25 mm D
(2.6" W x 4" H x 1" D)
» ABS plastic
Battery: » 9 V (ANSI / NEDA 1604, PP3 or equivalent) or
3V lithium battery
TRANSDUCER
Model: » XRS-5*
Refer to associated Transducer manual.
TEMPERATURE SENSOR
Model: » TS-2, LTS-1 or LTS-1C
Refer to associated Temperature Sensor manual.
CABLING
Transducer: » RG-62U coaxial
» maximum separation 183 m (600 ft)
» must be run in grounded metal conduit
mA Output: » Belden 8760 or equivalent
Synchronisation: » Belden 8760
Temperature Sensor: » Belden 8760, 1 pair shielded/twisted,
18 AWG or equivalent
» maximum separation 183 m (600 ft)
» can be run in conduit with transducer cable
Communication: » RS-232: » Belden 8770, 3 wire shielded, 24 AWG
or equivalent
» maximum separation 15 m (50 ft)
» Bipolar Current: » Belden 9552, 2 pair shielded/twisted,
18 AWG or equivalent
» maximum separation 1,500 m (5,000 ft)
*Note: The XRS-5 must be used with the TS-2 external temperature sensor when
operating with the OCM-3.
Velocity Input: » Belden 8760 or equivalent
7ML19985AB01 OCM III 11
Auxiliary Input: » Belden 8760 or equivalent
24 V Output: » Belden 8760
COMMUNICATION SOFTWARE
Milltronics Utilities Software on standard PC floppy disk for DOS 3.1 and up.
7ML19985AB01 OCM III 12
INSTALLATION
Installation shall only be performed by qualified personnel
and in accordance with local governing regulations.
INSTALLING THE OCM-3
The OCM-3 should be mounted in a clean, dry area that is: within the ambient
temperature range and suitable for the specified enclosure. The front cover should be
accessible for programming and viewing.
It is advisable to keep the OCM-3 away from high voltage or current runs, contactors
and SCR control drives.
Do not mount the OCM-3 in direct sunlight without the use of a sun shield.
This product is susceptible to electrostatic shock.
Follow proper grounding procedures.
OUTLINE AND MOUNTING
16 mm
(0.6")
209 mm
(8.2")
172 mm
(6.8")
267 mm
(10.5")
lid screws
(6 places)
285 mm
(11.2")
106 mm
(4.2")
91 mm
(3.6")
programmer
suitable location for
conduit entrances
Milltronics reccomends using a punch for making
holes in enclosure. Use suitable cable glands to
maintain ingress rating.
Non metallic enclosure does not provide grounding between connections.
13 OCM III 7ML19985AB01
mounting holes
(accessed under
lid 4.3 mm (0.17")
dia.,4 places
customer mounting
lid
enclosure
screw
Use grounding type bushings and jumpers.
OCM-3 LAYOUT
board A
display
board
board B
All field wiring must have insulation suitable for at least 250 V.
Hazardous voltage present on transducer terminals during operation.
dc terminals shall be supplied from SELV source in accordance
with IEC 1010-1 Annex H.
Relay contact terminals are for use with equipment having no accessible
live parts and wiring having insulation suitable for at least 250 V.
The maximum allowable working voltage between
adjacent relay contacts shall be 250 V.
14 OCM III 7ML19985AB01
SYSTEM DIAGRAM
OCM-3
mA output
relay output
auxiliary input
velocity input
Milltronics transducer,
see Specifications
Milltronics TS- 2,
temperature sensor
customer device
customer alarm,
pump or control
device
customer device
customer device
bi-polar current
(Milltronics communication)
Maximum syste m ca pability. Not all components or their maximum quantity
may be required.
15 OCM III 7ML19985AB01
RS-232
customer device
Milltronics CVCC
98/03/05
INSTALLING THE TRANSDUCER
Max cable run 183 m (600 ft) of
RG-62U or equivalent. Cable must
be run in a grounded metal conduit
with no other cabling (except
Temp. Sensor cable).
Ground shield at OCM-3 only.
Insulate shield at junctions to
prevent inadvertent grounding.
Basic Wiring – Transducer
Hazardous voltage present on transducer terminals during operation.
Note: When using the XRS-5 transducer with the OCM-3, use the TS-2 external
temperature sensor. The internal temperature sensor in the XRS-5 cannot be used.
INSTALLING THE TEMPERATURE SENSOR
In order to compensate for uniform
temperature change in the air
between the transducer and the flow
surface, the temperature sensor
must be connected to the OCM-3.
Maximum cable run 183 m (600 ft) of
Beldon 8760, 1 pair shielded/twisted,
18 AWG or equivalent.
Temperature sensor cable can be
run with the transducer cable in a
grounded metal conduit.
Ground shield at OCM-3 only.
Basic Wiring – Temperature Sensor
16 OCM III 7ML19985AB01
mA OUTPUT
RELAYS
isolated 0 or 4 to 20 mA output (P26) into 1 KΩ loa d maximum.
Wiring should conform to standard instrumentation practices.
Ground shield at OCM-3 only.
relays shown in de-energized state,
contacts rated at 5 A at 250 V
non-inductive.
n.c. com n. o. n.c. com n. o. n. c. com n. o.
All relays are certified for use in equipment where the short circuit capacity of the
circuits in which they are connected is limited by fuses having ratings not exceeding
the rating of the relays.
17 OCM III 7ML19985AB01
SYNCHRONIZATION
Where two to a maximum of twelve transducers will be sharing a common conduit the
OCM-3s should be synchronized. In order to synchronize OCM-3s:
» remove jumper J1 on board A on all but one OCM-3
» interconnect the SYNC terminal (TB1-20) of all OCM-3s. Insure that
all OCM-3s share a common ground (TB1-34).
18 OCM III 7ML19985AB01
POWER CONNECTIONS
The OCM-3 power supply accepts 100, 115, 200 or 230 V ac per switch SW1
(board B) selection and 9 to 30 V dc.
The OCM-3 operates either under ac or dc power, or both ac and dc live
simultaneously. If both ac and dc power are live, the OCM-3 normally draws power
from the ac supply. In the event that the ac supply fails, the OCM-3 then draws power
from the dc supply.
AC POWER
*
100/115/200/230 V ac, 50/60 Hz,
select voltage via switch on board B
* switch shown in
‘OFF’ position,
select appropriate
voltage.
The equipment must be protected by a 15 A fuse or
circuit breaker in the building installation.
A circuit breaker or switch in the building installation, marked
as the disconnect switch, shall be in close proximity to
the equipment and within easy reach of the operator.
DC POWER
19 OCM III 7ML19985AB01
nega tive dc input (T B1 - 24) is
9 to 30 Volt
dc input
tied to ground (TB1-34)
dc terminals shall be supplied from SELV source in accordance
with IEC 1010-1 Annex H.
INSTALLING THE MEMORY BACK-UP BATTERY
Disconnect power before installing or replacing the battery.
Do not install the memory back-up
battery until the OCM-3 is to be used.
The unit is supplied with one battery
package. Remove the battery from
the package and insert it into the
battery socket.
Refer to Operation \ Memory.
The memory battery, B1 (see Specifications) should be replaced yearly to insure
memory back up during lengthy power outages. An on board capacitor provides
one hour of memory retention in order to preserve the memory while the ba ttery
is being changed.
COMMUNICATING VIA COMPUTER
Refer to Communication.
INSTALLING THE PROGRAMMER
To program the OCM-3 via the Programmer, it must be placed into the front cover
recess of the OCM-3. The back of the Programmer has a magnetic plate which will
hold the programmer in place. It can be removed when programming is completed.
20 OCM III 7ML19985AB01
START UP
GENERAL
For the initial start up, it is advisable to use the programmer for programming the
OCM-3. The programmer transmits a coded infrared signal each time a key is pressed.
The OCM-3 is designed to automatically scroll through the ‘A’, ‘D’, ‘F’, ‘P’ and ‘U’
parameters in a structured sequence. The scrolling is interactive in that, depending on
the option chosen for a given parameter, subsequent parameters may be skipped or
modified. The user is thus prompted to satisfy only the parameters which are available
to him for the application he has chosen.
KEYPAD
numeric
entries with
decimal point
access to ‘D’, ‘F’,
‘P’ and ‘U’
parameters
negative
access to ‘A’ parameters
/ initiate s a printout while
viewing ‘Flow and T otal’
scrolls through selected
parameter options
scrolls
Forward
the parameters / enters
content of entry field
scrolls
Backward
parameters / clears content of entry field
through
through the
7ML19985AB01 OCM III 21
LEGEND
Press the associated programmer key:
Display shown on OCM -3:
Programmer key:
INITIAL START UP
After installation procedures have been completed, the OCM-3 may be powered up.
Upon initial powering up, the unit momentarily displays:
and then scrolls through the available languages:
The OCM-3 is asking which language you prefer to communicate in!
0
(0) language
F0 enter security code
< - - -
7ML19985AB01 OCM III 22
English
English language
selected
advance to ‘F0’
8 2 8
1
72
factory set security code
2.71828 must be entered
P0 language
0 English
P1 dimensional units
0centimeters
P0 language
0 English
if the wrong language
was selected, it may
be changed here
continue programming by
entering the desired options
and advancing until the
scroll returns to ‘P0’. It is
then assumed that the
user has entered all the
required parameters.
For optimum calibration accuracy, an ‘F13’ should be performed prior to accessing
‘F2’, the normal operating mode.
3
1
F13 auto zero calibration
enter the current head. The
OCM-3 calculates ‘P46’ and
automatically enters the value.
e.g. 1 6 0
01 6
F13 auto zero calibration
160
F13 auto zero calibration
0 completed
7ML19985AB01 OCM III 23
If data logging is desired, the time and date must be set.
4
F4 24-hr. time
e.g. 1141
4
1
1
1
F4 24-hr. time
1141
F4 24-hr. time
11:41:00 enter new time
11: 41 a.m.
seconds are always
assumed to be 00
time is displayed in
hh:mm:ss
,
F5 (ddmmyyyy) date
e.g. 12101492 October 12, 1492
0 1
4
9 211 2
F5 (ddmmyyyy) date
12/10/1492 enter new date
The start up procedure is now complete. Enter ‘F2’ to place the OCM-3 in the normal
operating mode.
2
Note: To save parameter values, return to RUN mode (F2) after programming.
The OCM-3 now displays the flow rate and total. Refer to Operation \ Display
7ML19985AB01 OCM III 24
FUNDAMENTAL CHECKS
For accurate determination of flowrate, accurate head measurement is essential.
Check the following and correct if necessary.
» check D5 for correct temperature at transducer location.
» check D9 for corre ct distance from transducer to head.
» check D0 for accurate head measurement.
7ML19985AB01 OCM III 25
7ML19985AB01 OCM III 26
OPERATION
Upon power up, the transducer is fired periodically as set by P36. A long interval
between measurements may be desirable in order to conserve power* when
operating the OCM-3 from a DC source of limited capacity.
The echo is processed to determine the head (D0). The flow rate (D1) is calculated by
the OCM-3 as a mathematical function (P3 and P4) of head or a function of head and
velocity (P42). The flow rate is then integrated to yield the totalized flow (D2). The
‘Flow’ and ‘Total’ fields which are displayed during the normal running mode (F2) are
also continuously updated.
Viewing or changing the content of a parameter (except F1, emulation) is done
without disturbing the acquisition, processing or logging of flow data (see \ Security).
*
restricted usage of display lighting (P14), relays (P15, 18 & 21), mA
output and communications will also conserve power.
MEMORY
During a power interruption, the memory back up will hold the programming, the log
and the totalizer values, and run the clock. The memory battery (B1) provides up to
one year of memory retention (see Appendices \ Maintenance).
Note: To save parameter values, return to RUN mode (F2) after programming.
SECURITY
The content of all ‘A’, ‘D’, ‘F’, ‘P’ and ‘U’ parameters can be viewed without having to
satisfy the security parameter, F0. However if it is desired to change the content of
any of these parameters, the security parameter must be satisfied (except for
resetting the running min/max displays, parameters D3/D4 and D6/D7).
Once security has been satisfied, a ccess continues for 5 minutes after the last key is
pressed or until F2 is re-entered.
The security code may be changed from its factory set value, 2.71828, by entering a
new value into F10. It is imperative that the new value be recorded, as the code can
not be viewed. If the code is lost, consult Milltronics.
UNITS
Programming of the OCM-3 involves setting the units of measure:
» P1 linear and velocity
» P2 temperature
» P5 flow rate and volume
If the units are changed during the course of operation, the change will be effected
through all associated parameters and displays and will rescale flow and total data
stored in the logs.
7ML19985AB01 OCM III 27
FLOW CALCULATION
Absolute vs. ratiome tric
The OCM-3 can be programmed to use eithe r of two methods (P4) for calculating flow
from the head measurement: absolute or ratiometric. The result is the same
regardless of the method used. The principal difference is the information that must
be entered in orde r for the OCM-3 to carry out the calculation. The user’s choice of
method may ultimately be based upon the information which is at hand. Refer to U
parameters for the primary element selected for a listing of the information required.
For the ratiometric method, it is usually sufficient that the user know the flow rate
) which occurs at maximum head (h
(Q
cal
On the other hand, absolute calculations require that the user enter information such
as: the physical dimensions of the primary element and the constant relating to units
of measure for both linear dimensions and flow rates.
e.g.
the general formula for flow through a single exponent primary element is:
cal
).
Q = KH
x
the specific formula for flow through a 45° V-notch weir is:
cfs = 1.03H
2.5
thus: Q = flow in cubic fe et per second
K = constant of 1.03
H = head in feet
The absolute method is not applicable to the following:
Palmer Bowlus flume
H flume
DISPLAY
The normal display during operation is the Flow and Total Display (F 2).
flow rate field
totalizer fie ld
7ML19985AB01 OCM III 28
relay / "no echo" field
status field
Flow Rate Field
Totalizer Field
flow rate
units, P5
total
multiplier, P32
Relay / No Echo Field
relay identification
under loss of echo
condition, "NO
ECHO" will
alternately flash
Status Field
relay status : 0 = relay de-energized
1 = relay energized
* = alarm state (indicated when
flashing)
The OCM-3 provides illumination for the LCD for easier viewing of the display.
Illumination can be set (P14) to be normally on or off, or automatic. When automatic is
selected, the lighting will automatically go on when keypad activity is sensed and then
extinguish after 15 seconds of inactivity.
For battery operation, set display lighting to off or auto.
DAMPING
The OCM-3 provides two separate damping functions: reading and mA output. Zero
or no damping allows fastest response while high or 100% provides the slowest
response. The damping is usually set to provide a reliable response without
sacrificing stability.
The reading damping, P13, dampens only the flow rate reading of the ‘Flow and Total’
display F2. The damping selections are: off, low, medium and high. Relay functions
associated with flow rate respond to the dampened reading values.
mA output damping, P27, dampens the change in the mA output. The parameter entry
is in seconds for spanning the 0 to 100% of the mA range selected (P26). Displays
and relay functions associated with the mA output respond to its
dampened value.
7ML19985AB01 OCM III 29
RELAYS
Three on board multipurpose relays are provided by the OCM-3. P15, 18 and 21 set
the respective functions for relays 1, 2 and 3. Depending on the function selected,
these parameters determine the need and configuration of the subsequent relay
control parameters, P16, 17 (relay 1); P19, 20 (relay 2) and P22, 23 (relay 3).
If the relay is to function as a driver for a remote totalizer or as a flow sampler contact,
the totalizer multiplier (P32) will be factored by the setpoint . Note that parameters
P16, P19, and P22 will default to zero. When a relay is set to totalizer (P32), you must
have the applicable parameter (P16 for relay 1, P19 for relay 2, or P22 for relay 3) set
to something other than zero (normally 1).
Example: For relay 1
Re la y totalizer factor =
totalizer factor (P32)
relay 1 setpoint (P16)
100 (P32=5)
=
2 (P16)
= 50 units/pulse
The status of each relay is shown in the display. Refer to \ Flow and Total Display.
For battery operation, have relays energizing on alarm.
mA OUTPUT
The OCM-3 provides a mA output (TB1-4/5) which can be assigned (P24) to
represent the measurement of flow, head, velocity or temperature. The associated
scaling, P25, is factory set to a value of ‘0’. This provides normal scaling with respect
to the assigned measurement.
Normal scaling for representation of flow, head or velocity is:
» 0 or 4 mA = 0
» 20 mA = maximum measurement value for: » P6
» P7: maximum head
Normal scaling for representation of temperature is:
» 0 or 4 mA = – 40 °C
» 20 mA = 60 °C
If custom scaling is required, the 20 mA corresponding value (other than 0) can be
entered into P25. The range (0 to 20 or 4 to 20 mA) and damping (see Damping) are
set via P26 and P27 respectively.
7ML19985AB01 OCM III 30
*
: flow rate
at maximum head
» P10: velocity
at maximum head
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