Geo SCADA Point Configuration — Analog, Digital, and Accumulator Points

Quick Answer

Points are the fundamental data objects in Geo SCADA. Each point represents a single process value — a pressure reading, a pump status, a flow totalizer, or a calculated value. Points are configured with a data type, source device, scaling parameters, alarm limits, and historian settings.

Point Types Overview

• Analog Input — Continuous values such as pressure, temperature, flow rate, and level. Stored as floating-point numbers.
• Digital Input — Binary states such as pump running/stopped, valve open/closed, or alarm active/normal.
• Accumulator — Totalized values such as flow volume or energy consumption. Accumulators track the running total and calculate periodic rates.
• String — Text values such as equipment status messages or batch identifiers.
• Time — Timestamp values for scheduling and event sequencing.

Creating an Analog Input Point

1. Right-click the target group in the database explorer.
2. Select New > Point > Analog Input.
3. Enter the point name (e.g., Pressure_Inlet_PSIG).
4. In the Source tab, link the point to a device and specify the register or DNP3 object index.
5. Configure scaling in the Input tab.
6. Set alarm limits in the Alarm tab.
7. Enable historian logging in the Historic tab.
8. Save the configuration.

Engineering Unit Scaling

Analog input scaling converts raw device values to engineering units. In the point's Input tab, configure:

• Raw Minimum / Maximum — The range of the raw value from the device (e.g., 0–65535 for a 16-bit register, or 4–20 for a 4–20 mA signal)
• EU Minimum / Maximum — The corresponding engineering unit range (e.g., 0–500 PSIG)

Geo SCADA performs linear interpolation between these bounds. For field devices such as the Bristol FB300 RTU, the raw values typically represent the ADC count or pre-scaled register value from the remote terminal unit.

Setting Alarm Limits

In the Alarm tab, configure up to four threshold levels:

• High High — Critical high alarm (e.g., emergency shutdown pressure)
• High — Warning high alarm
• Low — Warning low alarm
• Low Low — Critical low alarm (e.g., loss of suction pressure)

Each threshold supports individual deadband and time delay settings to prevent alarm chattering.

Historian Configuration Per Point

In the Historic tab, configure how the point's value is logged:

• Periodic — Log at a fixed interval (e.g., every 60 seconds)
• On Change — Log when the value changes by more than the configured deadband
• On Change with Periodic — Combine both methods for comprehensive coverage

Creating a Digital Input Point

Digital inputs follow the same creation process but represent binary states. Configure the State 0 and State 1 labels (e.g., "Stopped"/"Running" or "Closed"/"Open") and set alarm behavior for each state (e.g., alarm when pump is stopped unexpectedly).

Accumulator Points for Flow Totalization

Accumulator points track running totals from pulse-output devices such as flow meters. Configure the scale factor (pulses per unit volume), rollover value, and rate calculation interval. Geo SCADA automatically handles counter rollover and calculates flow rate from the totalizer delta.

Common Point Configuration Mistakes

• Incorrect raw range causing wildly inaccurate engineering unit values
• Alarm deadband too small, causing alarm chattering on noisy signals
• Historian deadband too large, missing significant process changes
• Missing source device linkage (point shows stale or no data)