Siemens 7ML19985AB01 instruction manual Fail-Safe, Flow Rate and Totalizing, Flow rate

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The mA function can be overridden for test purposes by setting the desired mA value into F3. When the value is entered, the mA output will go to that value. When F3 is exited, the mA output will revert to normal operation. Also, see \ Emulation Mode.

*In the case of absolute calculations (P4=0), P6 is calculated by the OCM-3.

FAIL-SAFE

In the event of an echo loss, the fail-safe timer will begin counting. If the echo loss duration surpasses that of the time set (P29), a ‘No Echo’ alert will be displayed in the Status field (see \ Display). The mA output will respond (P30) by either holding the last value or immediately going to a predetermined value (P31). The head and derived flow will hold their last value and totalization and logging will continue, based on that value. Upon resumption of a valid echo, the mA output will return to a value corresponding to the present value of the measurement assigned, at the mA damping rate (P27).

FLOW RATE AND TOTALIZING

Flow rate

Calculation of the flow rate is ongoing. It is normally viewed under the Flow and Total display (F2) with the decimal point set per P33. It can also be viewed under D1 as the raw flow calculation. Data on the running minimum and maximum flows that have occurred since the last reset can be viewed in two ways:

»F7 gives the running min/max flows and their time and date of occurrence since the last reset. F7 is reset by F8 but only after satisfying the security parameter F0.

»D3/D4 give the respective running min/max flow data, only, that have occurred since they were last reset. D3/D4 are reset simultaneously by entering 0 into either D3 or D4. D3 and D4 will then adopt the current flow rate and track the running min/max values from that point on. The security parameter (F0) does not need to be satisfied in order to reset D3/D4.

Flow data specific to a particular time and date can be viewed under the data log F14 (see \ Logging).

Totalizing

Totalizing of the calculated flow is ongoing. It is normally viewed under the Flow and Total display (F2).

An auxiliary totalizer (D2) is provided for operator usage and is intended for short term totalizing to a maximum count of 999999. It can be reset or preset independently of the F2 totalizer after satisfying the security parameter (F0).

In order to adjust the rate of filling of the totalizer, the totalizer multiplier (P32) can be set to an appropriate value. The totalizer can be reset via F11. Totalizing that is specific to the time and date can be viewed under the data log F14.

The OCM-3 can be programmed to operate a remote totalizer by assigning any of the relays (P15, 18 or 21) to act as a totalizer contact*. Under this function, the maximum rate of contact closure is 2/sec with a closure duration of 200 msec**.

*The totalizer count is set by the relay setpoint parameter (P16, 19 or 22 respectively).

**Typically the totalizer should be set for 300 to 3000 counts per day at maximum flow.

7ML19985AB01

OCM III

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Contents Open channel Contact Smpi Technical Publications at the following address Unit Repair and Excluded LiabilityTable of Contents General Keypad Initial Start Up Fundamental Checks Start UPOperation Appendices Maintenance Error Codes 100 Communications 101 7ML19985AB01OCM Short About thisIf you want to know about Read Product OCM IP65 enclosure Specifications» range 20 or 4-20 mA » resolution » 20 to 50 C -5 to 122 F» CE *, FM, CSA NRTL/C ProgrammerTransducer Temperature SensorCabling Auxiliary Input Communication SoftwareOutput » Belden Installing the OCM-3 InstallationOutline and Mounting OCM-3 Layout OCM-3 System DiagramCustomer device Ground shield at OCM-3 only Installing the TransducerInstalling the Temperature Sensor Ground shield at OCM-3 only Basic Wiring Temperature SensorRelays MA OutputSynchronization AC Power Power ConnectionsDC Power Communicating VIA Computer Installing the Memory BACK-UP BatteryInstalling the Programmer Disconnect power before installing or replacing the batteryGeneral Start UPKeypad English Initial Start UPOCM-3 is asking which language you prefer to communicate LanguageF13 auto zero calibration 160 Completed 7ML19985AB01 P0 language English P1 dimensional units CentimetersF5 ddmmyyyy date October 12 114124-hr. time 114100 Enter new timeFundamental Checks OCM Units OperationMemory Security = constant Flow Calculation Display Absolute vs. ratiometricDamping For battery operation, set display lighting to off or auto» P6 * flow rate For battery operation, have relays energizing on alarmExample For relay » 20 mAFlow Rate and Totalizing FAIL-SAFEFlow rate Capacity LoggingViewing the data log Blanking TemperatureTime and Date Reset Emulation ModeAs normal 7ML19985AB01 Flow Velocity InputAuxiliary Head Input Voltage Input Current InputDC Output Diagnostic Aids100% head 4 m, enter 5 m Nominal target range Security access required‘D’ Parameter Listing VelocityOCM ‘F’ Parameter Listing Enter security code Emulation modeKeypad to mA output OCM Linear Velocity ‘P’ Parameter Listing= centimetres = imperial million gallons per day Flowrate Volume= absolute = ratiometric Flow rate units GallonsOCM = 4-20 mA = 0-20 mA 7ML19985AB01 OCM OCM Variable condition FixedUnits OCM ‘U’ Parameters for P3 Primary Element OCM Reference U0 = exponent U1 = k factor P4 = 0 only= constant factor U1 = head Typical Weir Profiles Typical SHARP-CRESTED WeirsKhafagi Venturi Typical Parshall Flume Typical Leopold Lagco ‘U’ parameters required ‘U’ parameters calculated BS-3680 Rectangular Flume = crest width = Cv = crest height = Cd = crest length = a BS-3680 Round Nose Horizontal Crest Weir ¤ Refer to Operation \ Flow Calculation 7ML19985AB01 Cv = velocity coefficientBS-3680 Trapezoidal Flume BS-3680 U-Flume, P3 = BS-3680 U-FLUME = head H and p applied to C = crest width = C = crest height = Cp = crest lengthBS-3680 Finite Crest Weir = crest width He = effective head h + Kh = head Kh = 1 mm = Ce x 2⁄3 ⎯⎯√2⎯g x be x he1.5 Where q = flow rate= approach width = Ce = crest width = K b = crest height = gravitational accelerationBS-3680 Thin Plate Rectangular Weir U0 = notch angle Alpha U1 = Ce BS-3680 Thin Plate V-NOTCH Weir U0 = crest width b Rectangular Weir Contracted = hydraulic radius = slope of hydraulic gradient Based on the Manning FormulaRound Pipe U0 = maximum flume width, hmax PALMER-BOWLUS Flume U0 = maximum listed head, hmax Flume U0 = number of data points n, 4 to Universal Head vs FLOW, P3 =Flow, point A19 Flow, point A13 Head, point A14Flow, point A15 Head, point A16 Flow, point A17 Head, point A18U0 = channel width B U1 = area h Rectangular Area X Velocity = head, cm = flow velocity, cm/sec Trapezoidal Area X Velocity For h ≥ d = B b/d Where q = flow rate, l/s= channel top width, cm = head, cm = channel base width, cm Modified Trapezoidal Area X Velocity U0 = base diameter D U1 = area h Channel Area x Velocity U0 = conduit diameter U1 = area h Circular Area X Velocity GULL-WING Area X VELOCITY, P3 = Gull Wing Area X Velocity EGG-SHAPED Area X VELOCITY, P3 = EGG-SHAPED Area X Velocity Typical open channel Universal Area X VELOCITY, P3 =Area Head Universal Area X VelocityA10 = OCM Maintenance Error Codes Computer Customer’sSerial printer 102 Protocol for the OCM-3 is as follows Baud rateRefer to Cvcc Instruction DB-9 connectorDB-25 connector Bipolar CurrentP35 = 7, print interval set for 7 minutes Date104 Remote OCM-3 display Local display Utilities Software Programmer Remote OCM-3 programming105 106 107 Typical OCM-3Display value 00.000000 99.12399.123000 7ML19985AB01Response # = 0 through Content of P5Stop data log down load Start data log down load109 Computer Telephone lines Remote modem DB-25 connector 7ML19985AB01Standard modem CableConnect Establishing Communication111 112 Ending CommunicationRev
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