How do I configure analog inputs in PMCE for the FB300?

In the PMCE Project Navigator, select the analog input card slot and configure each channel with a point name, input type (4-20 mA, 1-5 V), zero and span values for engineering-unit scaling, alarm limits (HH, H, L, LL with deadbands), input filter time constant, and scan rate. Verify by applying 4 mA and confirming the zero value reads correctly.

What is input filtering in PMCE and how should I set it?

Input filtering smooths noisy analog signals using a time constant in seconds. Use 1-3 seconds for pressure, 3-10 seconds for level, 5-15 seconds for temperature, and 1-2 seconds for flow. Higher values smooth more but add lag. Don't over-filter flow signals or you'll mask real process changes.

How do I prevent alarm chattering in PMCE?

Set a deadband on each alarm threshold — typically 1-2% of the measurement span. The deadband creates a hysteresis zone so the alarm doesn't toggle rapidly when the process value oscillates near the setpoint. Without deadbands, operators experience alarm fatigue and may start ignoring real alarms.

PMCE I/O Configuration for the Bristol FB300: Analog and Digital Point Setup

Quick Answer

PMCE configures Bristol FB300 I/O points through the Project Navigator's hardware tree. Each physical channel is mapped to a logical point with a name, engineering-unit scaling, alarm setpoints, and scan rate. Proper I/O configuration is the foundation of reliable SCADA data.

Analog Input Configuration

Step 1 — Add the Analog Input Module

In the PMCE Project Navigator, expand the hardware tree and right-click on the I/O slot where the analog input card is installed.
Select the correct card model (8-channel or 16-channel, mA or mV range). The card model must match the physical hardware or PMCE will report a mismatch error on download.

Step 2 — Configure Each Channel

For each analog input channel, set these parameters:

Parameter	Description	Example
Point Name	Logical tag name for this input	`TK101_LVL`
Input Type	Signal type (4–20 mA, 1–5 V, TC)	4–20 mA
Zero	Engineering value at 4 mA (low end)	0.0 (feet)
Span	Engineering value at 20 mA (high end)	30.0 (feet)
Units	Engineering units label	FT
Filter	Input filter time constant (seconds)	2.0
Scan Rate	How often this channel is read	1 second

Step 3 — Configure Alarm Limits

For each analog point, PMCE allows four alarm thresholds:

HH (High-High): Emergency shutdown threshold — triggers immediate protective action (e.g., 28.5 ft tank level closes the inlet valve).
H (High): Warning threshold — alerts the operator to take corrective action (e.g., 25.0 ft).
L (Low): Warning threshold — alerts to low-level condition (e.g., 2.0 ft).
LL (Low-Low): Protection threshold — shuts down pumps to prevent dry running (e.g., 1.0 ft).

Set a deadband on each alarm (typically 1–2% of span) to prevent chattering when the process value oscillates near the setpoint.

Step 4 — Configure Input Filtering

The input filter smooths noisy signals. A higher filter time constant produces a smoother reading but introduces lag. Guidelines:

Pressure: 1–3 seconds (fast-responding transmitters with pulsation dampeners).
Level: 3–10 seconds (float or radar level transmitters in turbulent tanks).
Temperature: 5–15 seconds (thermowell thermal lag already smooths the signal).
Flow: 1–2 seconds (avoid over-filtering which masks real flow changes).

Digital I/O Configuration

Digital Inputs

For each digital input channel, set:
- Point Name: (e.g., PMP201_RUN)
- Input Type: Dry contact or wetted contact
- Normal State: Normally open (NO) or normally closed (NC) — this determines the "normal" vs "alarm" state display
- Debounce: Filter time to prevent false triggers from contact bounce (typically 50–200 ms)
Set alarm priority — critical (safety shutdown), high (process alarm), medium (operational), or low (diagnostic).

Digital Outputs

For each digital output channel, set:
- Point Name: (e.g., PMP201_START)
- Output Type: Momentary (pulse) or maintained (latched)
- Pulse Duration: For momentary outputs, the ON time in seconds (e.g., 2 seconds for a motor starter pulse)
- Fail-Safe State: What state the output should take on RTU restart or communication loss (ON or OFF)
Configure output interlock logic in the control task to prevent unsafe output states (e.g., don't start a pump if the discharge valve is closed).

Pulse Counter Configuration

For turbine flow meters and other pulse-output instruments:

Set the K-Factor (pulses per unit volume) from the meter calibration certificate.
Set the units (BBL, MCF, gallons).
Configure accumulation — the FB300 maintains both instantaneous flow rate and accumulated total volume.
Set the daily rollover time if using daily accumulators for production reporting (typically midnight or 07:00 gauge time).

Common PMCE I/O Configuration Mistakes

Wrong card model selected: PMCE compiles without error but the download fails or I/O doesn't scan because the configured card type doesn't match the physical card.
Zero/span reversed: The reading goes backward — high process value shows low reading. Always verify by applying 4 mA and confirming you see the zero value.
Missing filter on noisy inputs: Unfiltered readings from vibrating pipes or electrically noisy environments cause false alarms and erratic control.
No deadband on alarms: Alarm chattering when the process value hovers near a setpoint — operators get "alarm fatigue" and start ignoring real alarms.
Duplicate point names: PMCE allows duplicate names in different tasks but this causes confusion when mapping to DNP3 or SCADA. Enforce unique names project-wide.