BACnet/IP to 4 Utility Meters (pulse – B6070)

Description

Field I/O to pulse meters using a TCP/IP network

Collecting pulse outputs from devices using a BACnet/IP Collection Client Computer

Generally pulse output devices have documentation which indicates how many pulse for how much flow. And one can use various methods to get the calibration factors.

Then one wants to collecting the pulses in an ongoing fashion.

With BACnet client software and a Cimetrics B6070 four channel pulse collection device, one can accomplish this connectivity.

The BACnet/IP port on the B6070 connects to the network Ethernet/TCPIP port using a standard CAT5 cable. The pulse input I/O connects to the target pulse output devices (this can be almost any cable pair shorter than about 20 feet).

Perhaps the most important feature of the B6070 is its non-volatile storage of pulses it sees. While it is powered on it will always get pulses and never lose them, even through power outages. This is unlike most digital IO on control system modules. They can certainly count pulses, but, one way or another, often lose counts at power down or at times when their program is reloaded. In fact with a B6070 one cannot reset the pulse count short of returning the B6070 to the factory. The counts are stored in 32bit non-volatile registers and in most normal applications, there is little danger of roll-over during the devices lifetime.

The B6070 is best at accepting dry contact closures. These can be from relays, or KYZ outputs on meters or reed switches or others. The pulse capture frequency range is from DC to 45Hz. The inputs can sense pulses as short as 10 milliseconds allowing duty cycles of down to ten percent at maximum frequency. The inputs are optically isolated and internally excited with DC-DC converters. This allows one spurious ground/potential to be present in any contact pulse source. Contact chatter is compensated for in both optical isolation hardware and software sensing.

The B6070 can be powered from any 5VDC, 300mA+ source (one possibility is to use a special non-communication USB to 5VDC adapter, another is to use a 802.3af Power over Ethernet injector, and still another is to use the included 5VDC power supply).

The B6070 is setup using its embedded webpages. The scale factors and pulse offsets can entered to get the desired BACnet Analog Value portrayal of the devices.

The B6070 provides a BACnet/IP interface for commodity/utility flow meters that have a pulse output. This allows integrators to use simple meters. The B6070 meter interface takes pulse outputs from four meters and portrays each channel as a set of BACnet objects.

The B6070 is enclosed in a DIN case that can be mounted standalone or on a DIN rail. It is powered by 5 VDC at 1A via a micro USB connector which can be supplied from an included external 50-60Hz and 100-240 VAC supply. The unit has two four-pin inline Euro-style 5mm plug connectors for pulse channel inputs and one Ethernet 10/100 RJ45 connector.

There are (4) pulse input channels. The pulse input channels are each optically isolated. Each channel is self-powered through a DC-DC converter. Each channel can tolerate one stray potential/ground. This is optimal for flow meters with dry contact closure outputs, and which might have stray grounds somewhere in their output circuits (water meters often have such stray voltages).

The Ethernet port uses a standard shielded RJ45 connector with integral LEDs. Connection status can quickly be determined from the Link and Activity LEDs on each interface.

An embedded web server allows for commissioning, configuration and troubleshooting via a standard web browser. A power LED is present along with the LEDs for interface status on each interface.

The meter pulse counts are stored to flash memory. When the device senses a loss of power it will immediately write the latest pulse count so that data is not lost. This raw pulse value is made available to the BACnet network as an analog object. Scale factors are able to be selected during setup so that the appropriate scaled usage data (gas, water, electrical) is also available as a BACnet analog object.