Jim ‘Slim’ Mimlitz, SCADAmetrics
The model HbMag, by Mueller Systems (Cleveland, NC), is a versatile, battery-powered magnetic flow meter that is suitable for monitoring totalization and rate-of-flow in municipal potable water applications. This meter is the same as the Siemens FM Mag8000, and therefore this article applies equally to this meter, as well.
The HbMag features two main signal outputs: a 3-wire Sensus-protocol encoded AMI output, and a 2-wire open-drain output. Derivatives of both the 3-wire AMI output and the 2-wire open-drain output may be used to connect the HbMag to SCADA systems.
Generally speaking, if the HbMag is staged within a controlled dry environment, then our SCADA interface solution centers around using the SCADAmetrics model APK Analog/Pulse Kit to interface with the HbMag’s 2-wire open-drain output. If the HbMag is staged within a wet pit environment, then our SCADA interface solution centers around using the SCADAmetrics model EMP Signalizer to interface with the HbMag’s 3-wire AMI output.
Analog/Pulse Kit Solution — Generates Multiple SCADA Signals for HbMag
The SCADAmetrics models APK and APK.PLUS Analog/Pulse Kits are built to serve as signal gateways between the HbMag and SCADA system, thereby providing the following auxiliary signals:
- 4-20 milliamp rate-of-flow signal
- Pulse-per-volume (dry contact) signal
- Flow-Switch (dry contact) signal, or 2nd Pulse-per-volume signal
AMI and SCADA wiring is via the internal terminal block of the HbMag. The register lid may be removed by loosening the two (2) set screws on opposite sides of the register and carefully twisting the register lid to remove. Internal wiring is straightforward, as illustrated below.
HbMag.Terminal.56 should be connected to APK.Terminal.2. HbMag.Terminal.57 should be connected to APK.Terminal.3. APK.Terminal.1 should be left disconnected.
HbMag Terminals [91,92,93] correspond to AMI [Clock (Red), Data (Green), Common (Black)].
Note that the model APK is typically mounted inside a control panel on din-rail. However, if a concurrent visual rate-of-flow display is desired, then the aforementioned model APK can be replaced with the model APK.PLUS, which is rated NEMA-4X and is wall-mountable. The SCADA outputs of the APK.PLUS are identical to those in the APK:
Signalizer Solution — Generates Multiple SCADA Signals for HbMag
The SCADAmetrics model EMP Signalizer is built to serve as signal gateways between the HbMag and SCADA system, thereby providing the following auxiliary signals:
- 4-20 milliamp rate-of-flow signal
- Pulse-per-volume (dry contact) signal
- Alarm (dry contact) signal (alarm = cut cable or loss-of-power to Signalizer)
AMI and SCADA wiring is via the 3-wire encoder cable of the HbMag. If the HbMag is outfitted with a Nicor cable, then the Nicor mating connector should be cut off, exposing the 3 internal wires (red, green, black). Internal wiring is also illustrated below.
HbMag Terminals [91,92,93] correspond to AMI [Clock (Red), Data (Green), Common (Black)].
Factory-standard encoder resolution is detailed in the first table below. For optimal performance, we recommend that the HbMag be re-programmed for higher-resolution, as detailed in the second table below.
Both of the afore-illustrated solution options feature the model EMP Signalizer and the model APK Analog/Pulse Kit. As an upgraded alternative to the APK, the model APK.PLUS may also be used if a remote visual interface is required. When a customer utilizes the Signalizer and Analog/Pulse Kit families in conjunction with the HbMag, a modular SCADA signaling architecture is achieved, providing the customer with the following benefits:
- Use of a Single, Standard, AWWA-style Magnetic Flow Meter is Possible, Rather than a Specialty 4-20mA Flow Meter, or Two Meters.
- Hardware-Only Solution — No PLC (Programmable Logic Controller) Programming Required.
- Both Analog/Pulse Kit and Signalizer Provide Optically-Isolated Power and I/O Circuitry for Superior Lightning Protection.
- DC Low-Voltage Wiring for Increased User Safety.
- Compact, DIN-Rail Footprint Signalizer or Analog/Pulse Kit, for Easier Integration inside the Control Panels.
- User-Settable DIP Switches Allow Analog/Pulse Kit to be Used with Various HbMag Sizes, Eliminating Need for Factory Programming.
- User-Selectable 4-20 Milliamp Span (Digitally Self-Calibrated).
Want to Learn More?…
Are you interested in learning more about how SCADAmetrics flow instrumentation can be leveraged to expand the capabilities of the Mueller HbMag? Give us a call!… We’ll be glad to discuss the details!