Jim ‘Slim’ Mimlitz, SCADAmetrics
Along with support for almost all major AWWA-style, encoder-equipped water meters, the EtherMeter also supports generic pulse-type meters, as well. Please see Chapter 9 of the EtherMeter User Manual, which provides detailed wiring and setup support for pulse-type meters.
This article describes the firmware setup required for the GF 2551 Insertion Magnetic Flow Meter, but could be extended to apply to all GF pulse meter types.
When setting up the EtherMeter for a pulse-type meter, the user is required to specify a few pulse-specific settings via Serial Terminal or Telnet:
- PWRn=0 (tells EtherMeter meter is pulse-type)
- DBn=0 to 10000 (debounce filter, in milliseconds, 0=disabled/recommended)
- PDn=Pulse Divisor
- PSn=Pulse Scalor
The PDn/PSn Ratio defines the number of Pulses-per-Volume (for example, Pulses per Gallon).
In the example of a George Fisher Model 2551 Insertion MagMeter, the PDn/PSn ratio is simply derived from the K-Factor Table, which can be picked according to the pipe diameter and saddle-type from the 2551 User Installation Manual:
Example: SCH 80 PVC SADDLES FOR SCH 80 PVC PIPE
- K-Factor = 83.89 (Pulses per Gallon)
- Therefore, PDn=8389 and PSn=100 (8389 pulses per 100 Gallons)
The 2551 should be set to “frequency output” (blue jumper ON), and 2551.Terminal.2 of the MagMeter (open-collector signal) should be direct-wired to EtherMeter.Terminal.15 (ch.1) or EtherMeter.Terminal.18 (ch.2). The 2551 should be externally-powered using the same 24VDC as the EtherMeter, where the 24VDC power hookup is 2551.Terminal.1 (+) and 2551.Terminal.3 (-). No auxiliary 10K pull-up resistor is required, as that is provided internally by the EtherMeter.
Note that the Signet MagMeter Manual requires that the DC common be grounded. Therefore, for isolated output power supplies, it is important to connect Earth Ground to the Power Supply DC Common with a Jumper Wire.
Are you interested in utilizing the SCADAmetrics EtherMeter as a Modbus or Allen-Bradley Gateway to your George Fisher Insertion Magnetic Flow Meters? Give us a call, and we’ll be glad to discuss the details!