Wiresheet Vs IQset Logic Comparisons?

Here is a useful article, especially written for engineers migrating from Trend IQ/Vision/963 systems to Tridium Niagara N4. It’s more than just a name comparison and includes functional equivalence, migration notes, and gotchas, because many blocks do not have a direct 1:1 mapping.

Trend vs Tridium Block Names

Purpose

This document provides a quick reference for engineers transitioning between Trend IQSET strategy programming and Tridium Niagara N4 wire-sheet programming.

Important: A direct block-for-block replacement is not always possible.
Niagara generally uses a component-based architecture where functionality may be distributed across multiple components.

Input / Output Objects Table

Trend	Tridium Niagara	Notes
Analogue Input (AI)	NumericPoint (Proxy Point)	Physical network or field input. Not equivalent to NumericWritable.
Analogue Output (AO)	NumericWritable	Writable numeric value used to command outputs.
Digital Input (DI)	BooleanPoint (Proxy Point)	Physical network or field input.
Digital Output (DO)	BooleanWritable	Writable digital command point.
Virtual Analogue Variable	NumericWritable	Common replacement for Trend strategy variables.
Virtual Digital Variable	BooleanWritable	Common replacement for digital strategy variables.
Sensor Module	NumericPoint / BooleanPoint	Usually a network or hardware sourced point.
Strategy Variable	NumericWritable / BooleanWritable / Control Point	Depends on data type and intended use.
Supervisor Point	Station Point	Similar supervisory function.
LAN Data / IC Comms Value	Network Point / Proxy Point	Typically exposed through a Niagara driver.

Basic Logic Blocks

Trend	Tridium Niagara	Notes
AND	BooleanAnd	Same function
OR	BooleanOr	Same function
NOT	BooleanNot	Same function
XOR	BooleanXor	Same function
NOT Equal	NotEquals	Same function
Equal	Equals	Same function
Greater Than	GreaterThan	Same function
Less Than	LessThan	Same function
Greater Or Equal	GreaterOrEqual	Same function
Less Or Equal	LessOrEqual	Same function

Mathematical Functions

Trend	Tridium Niagara	Notes
ADD	NumericAdd	Same function
SUBTRACT	NumericSubtract	Same function
MULTIPLY	NumericMultiply	Same function
DIVIDE	NumericDivide	Same function
MINIMUM	NumericMin	Same function
MAXIMUM	NumericMax	Same function
AVERAGE	NumericAverage	Same function
ABS	NumericAbs	Same function
SQUARE ROOT	NumericSqrt	Same function

Trend Timer Functions vs Niagara Equivalents

Trend Function	Niagara Equivalent	Notes
Timer	Timer, BooleanDelay, NumericDelay	No direct 1:1 equivalent. Niagara provides several timer-related components depending on the required behaviour.
Delay	BooleanDelay / NumericDelay	Closest equivalent to Trend Delay modules. Supports configurable on and off delays.
On Delay	BooleanDelay (On Delay mode)	Direct functional equivalent for delaying an output transition to true.
Off Delay	BooleanDelay (Off Delay mode)	Direct functional equivalent for delaying an output transition to false.
Pulse Timer	OneShot	Generates a timed pulse from a trigger event. Similar to Trend pulse generation.
Hours Run	ElapsedActiveTime, DiscreteTotalizerExt	Usually implemented as an extension attached to a Boolean point rather than a standalone logic block.
Starts Counter	Counter, ChangeOfStateCount	Used to count equipment starts or state changes.
Runtime Counter	ElapsedActiveTime	Tracks accumulated active runtime of a Boolean signal.
Pulse Generation	OneShot, MultiVibrator	Depends on whether a fixed pulse or repeating pulse train is required.
Flasher/Oscillator	MultiVibrator	Generates alternating on/off outputs at configurable intervals.
Real Time Clock	CurrentTime, TimeService	Provides system time information rather than timer functionality.
Scheduled Timer	BSchedule + Logic Components	Niagara typically combines schedules with logic rather than using a dedicated timer module.

Migration Note

Trend's Timer module represents several different timing functions, whereas Niagara separates these into dedicated components such as BooleanDelay, NumericDelay, OneShot, Counter, ElapsedActiveTime, MultiVibrator, and schedule objects. When converting strategies, it is important to match the required behaviour rather than simply selecting a Niagara "Timer" component.

Trend Timer functionality may require several Niagara components depending on application.

Control Loops

Trend	Tridium Niagara	Notes
PID	kitControl LoopPoint	Primary Niagara PID controller. Closest equivalent to Trend Loop/PID modules.
SEQ	SequenceLinear / SequenceBinary	Depends on whether analogue or digital sequencing is required.
RAMP	Ramp	Similar rate-of-change functionality.
RATE LIMIT	Ramp / Rate Limiting Logic	Niagara typically uses Ramp for output slew-rate limiting.
HYSTERESIS	Hysteresis	Direct functional equivalent.
OPTIMUM START/STOP	OptimizedStartStop	Available in kitControl Energy palette. Similar purpose but different configuration methodology.

Selection & Switching

Trend	Tridium Niagara	Notes
MAX SELECT	NumericMax	Similar
MIN SELECT	NumericMin	Similar
HIGH SELECT	NumericMax	Similar
LOW SELECT	NumericMin	Similar
SWITCH	NumericSwitch	Similar
DIGITAL SWITCH	BooleanSwitch	Similar
PRIORITY SWITCH	Writable Point + Priority Array	Different architecture

Analogue Signal Processing

Trend	Tridium Niagara	Notes
SCALE	LinearConvert	Similar
CLAMP	LimitNumeric	Similar
OFFSET	NumericAdd	Add constant
GAIN	NumericMultiply	Multiply factor
FILTER	NumericFilter	Similar
LIMIT	LimitNumeric	Similar

Clock and Scheduling Table

Trend	Tridium Niagara	Notes
CLOCK	CurrentTime / TimeService	True clock source.
REAL TIME CLOCK	TimeService	Station-wide time service.
TIMESWITCH	BSchedule	Closest Niagara equivalent.
SCHEDULER	BSchedule	Primary scheduling component.
CALENDAR	CalendarSchedule	Supports holidays and exceptions.
OPTIMUM START	OptimizedStartStop	Requires Energy module and space temperature inputs.
SCHEDULE OFFSET	Schedule Logic + Priority Writes	Usually implemented using schedules and writable points.

Alarm Handling

Trend	Tridium Niagara	Notes
ALARM BLOCK	NumericAlarmExt / BooleanAlarmExt	Niagara alarm extensions
ALARM MASK	AlarmClass / AlarmFilter	Different implementation
RETURN TO NORMAL	Alarm State	Automatic in Niagara

Event Generator

Trend	Niagara
EVENT GENERATOR	Alarm Extension
RETURN TO NORMAL	Automatic Alarm State

Because most engineers will attach a NumericAlarmExt or BooleanAlarmExt rather than create something called an "Alarm Source".

Network Communications

Trend	Tridium Niagara	Notes
ICOM	Driver + Proxy Point Architecture	Niagara communications are driver-based rather than module-based.
IC Comms	Network Point / Proxy Point	Data exchange occurs through driver-exposed points.
LAN Data	Network Point	Similar concept but implemented differently.
BACnet Device	BACnet Device + Proxy Points	Direct equivalent.
Modbus Device	Modbus Device Network	Direct equivalent.
M-Bus Device	M-Bus Driver Device	Requires appropriate Niagara driver.
XNC Interface	Vendor Driver / Integration Module	Depends entirely on protocol and driver availability.

Priority Handling Table

Trend	Tridium Niagara	Notes
Priority Switch	Writable Point + Priority Array	No dedicated switch block equivalent.
Manual Override	Priority Write	Typically written at a higher priority level.
Hardware Command	Priority Write	Usually occupies a dedicated priority level.
Emergency Override	Priority Array	Highest priorities reserved for emergency control.
Direct Output Write	Writable Point	Niagara outputs are generally commanded through priority arrays.

Additional Trend Driver Module Mapping

Trend Driver Module	Tridium Niagara	Notes
Raise Lower with End Stop	RaiseLower	Closest functional equivalent.
Raise Lower Continuous	RaiseLower	Widely used for actuator positioning.
Time Proportional	LoopPoint + TimeProportional Logic	May require multiple Niagara components.
Binary Hysteresis	Hysteresis	Similar behaviour.
Multistage Digital	SequenceBinary	Common staging solution.
Analogue Driver	NumericWritable	Direct command output.
Digital Driver	BooleanWritable	Direct command output.

SCALE | LinearConvert |

SCALE	LinearConvert / NumericMultiply + NumericAdd

Many Trend scale blocks are actually doing:

Output = (Input × Gain) + Offset

which often becomes Multiply + Add.

Strategy Execution Differences

Trend	Niagara
Compiled strategy executes sequentially	Components execute based on slot changes and framework processing
Execution order usually explicit	Execution order often implicit
Variables live within strategy	Values exist as station components
Logic centralised in strategy	Logic distributed throughout station

That single table would explain more Niagara troubleshooting issues than almost anything else.Additional Migration Gotchas

Subject	Notes
Status Values	Niagara values contain both a value and status (OK, Fault, Down, Disabled, Overridden). Trend values are generally value-only.
Null Values	Niagara often propagates Null, Fault and Down conditions through wiresheets.
Point Extensions	Alarming, histories and runtime accumulation are commonly added as extensions rather than strategy blocks.
Priority Arrays	Niagara output control is heavily priority-based and differs significantly from Trend output writes.
Driver Architecture	Communications are driver-centric rather than ICOM-centric.
Logic Distribution	Niagara logic is often spread across points, schedules, histories, alarms and wiresheets rather than existing within a single compiled strategy.

Common Migration Gotchas

1. Strategy vs Wire Sheet

Trend strategies are executed as a compiled control sequence within a controller.

Niagara uses a component model where points, logic, schedules, alarms and histories are often separate objects linked together through wires.

2. Direct Equivalents Don't Always Exist

Examples:

Trend Block	Niagara Equivalent
PULSE	OneShot
SEQ	Combination of Sequencer + Logic
OPTIMUM START	Module dependent
ICOM	Driver dependent

3. Priority Handling

Trend commonly writes directly to outputs.

Niagara typically uses:

Priority Arrays
Writable points
Override levels
Emergency priorities

Understanding Niagara's priority architecture is critical when converting strategies.

4. Alarms Work Differently

Trend alarms are often embedded in strategy logic.

Niagara alarms are generally attached as extensions to points, providing:

Routing
Escalation
Acknowledgement
History
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