Calculating Array Data Collected by PLC Collector

SpeeDBee Synapse:v4.9.9Last updated:2026-09-04

Purpose

Convert data collected by PLC Collector as an array from a continuous memory area into a format that Compute Collector can use, then perform calculations on it.

Project files

These are the project files used in this example. A standard version and a version with the PLC Collector configured in simulation mode are available.

• PlcCollectorArrayCalculate.sspj
• PlcCollectorArrayCalculate_Sim.sspj (simulation mode)

Note: Import requires SpeeDBee Synapse version 4.9.9 or later.

What you will learn

• How to pass array data collected by PLC Collector to Compute Collector
• Why ARRAY SPLIT in Data Conversion is needed
• The workflow for decomposing array data into individual data items and using them in calculations

Requirements

Collect temperature data from multiple points in a PLC as an array from a continuous memory area, then calculate the average temperature and temperature differences using each value.

In this example, PLC Collector collects the following array data.

Data name	Address example	Data type	Array length	Description
temperature_values	D0100	WORD	4	Four temperature values (0.1°C units)

Each array element corresponds to the following measurement point.

Element	Description
temperature_values[0]	Inlet temperature
temperature_values[1]	Center temperature
temperature_values[2]	Outlet temperature
temperature_values[3]	Ambient temperature

Based on this data, create the following calculated values.

Calculated value	Description
average_temperature_c	Average of inlet, center, and outlet temperatures (°C)
inlet_outlet_diff_c	Difference between inlet and outlet temperatures (°C)
center_ambient_diff_c	Difference between center and ambient temperatures (°C)

Calculating array data

Currently, Compute Collector cannot use array data directly as calculation input. PLC Collector can collect a continuous memory area as an array, but before passing the data to Compute Collector, the elements used in calculations must be extracted as normal data items. Use ARRAY SPLIT in Data Conversion for this extraction.

Components used

• PLC Collector (array data collection)
• Data Conversion (array data decomposition)
• Compute Collector (calculations using decomposed data)

Workflow

1. Collect four temperature values as an array from a continuous memory area with PLC Collector
2. Decompose the array data received from PLC Collector into individual elements with Data Conversion
3. Pass the decomposed data to Compute Collector
4. Use the decomposed temperature data in Compute Collector to calculate and output the average temperature and temperature differences

Setup

1. Configure PLC Collector. Specify the PLC connection target, address, data type, array length, and other settings so that the four temperature values can be collected as an array. In this example, four temperature values are collected from D0100 as temperature_values.

   

2. Add Data Conversion and connect it to PLC Collector. When registering a new Data Conversion component, a dialog appears to select the component to connect to the input port. Select the PLC Collector configured in step 1 and click CONNECT.
   Note: PLC Collector must be running before it can be selected. Start it beforehand. It can also be started using the ▶ button.

3. Configure ARRAY SPLIT in Data Conversion. Select the array data received from PLC Collector and configure it so that the elements used in calculations are output as individual data items.

   Output each element of temperature_values with a name that makes the measurement point clear.

   

   Source data	Decomposed data example
   temperature_values[0]	temperature_inlet_raw
   temperature_values[1]	temperature_center_raw
   temperature_values[2]	temperature_outlet_raw
   temperature_values[3]	temperature_ambient_raw

4. Add Compute Collector and connect it to Data Conversion. When registering a new Compute Collector, a dialog appears to select the component to connect to the input port. Select the Data Conversion component configured in step 3 and click CONNECT.
   Note: Data Conversion must be running before it can be selected. Start it beforehand. It can also be started using the ▶ button.

   

5. Configure the calculation formulas in Compute Collector. First, in the input data settings, assign the temperature data extracted by ARRAY SPLIT to $A, $B, $C, and $D.

   

   Variable	Input data
   $A	temperature_inlet_raw
   $B	temperature_center_raw
   $C	temperature_outlet_raw
   $D	temperature_ambient_raw

   After configuring the input data, create the required calculation formulas using variables such as $A. In this example, the PLC values are assumed to be in 0.1°C units, so multiply by 0.1 to convert them to °C.

   

   Data name	Formula	Description
   average_temperature_c	(($A + $B + $C) / 3.0) * 0.1	Average of inlet, center, and outlet temperatures (°C)
   inlet_outlet_diff_c	($C - $A) * 0.1	Difference between inlet and outlet temperatures (°C)
   center_ambient_diff_c	($B - $D) * 0.1	Difference between center and ambient temperatures (°C)

6. Save the settings and start each component.

   

Checking the output

Check the output data from Compute Collector and verify that the calculation results are output using the decomposed data.

RAW values after ARRAY SPLIT

Check the RAW values decomposed by Data Conversion (ArraySplitter). You can see that each element of temperature_values collected by PLC Collector is output as an individual temperature data item.

Decomposed data	Value	Converted value
temperature_inlet_raw	247	24.7°C
temperature_center_raw	268	26.8°C
temperature_outlet_raw	282	28.2°C
temperature_ambient_raw	231	23.1°C

Calculated output values

Check the output from Compute Collector (CalculateTemperatureMetrics). You can see that the average temperature and temperature differences are output using $A, $B, $C, and $D assigned in the input data settings.

Calculated data	Value	Description
average_temperature_c	26.567	Average of inlet, center, and outlet temperatures (°C)
inlet_outlet_diff_c	3.5	Difference between inlet and outlet temperatures (°C)
center_ambient_diff_c	3.7	Difference between center and ambient temperatures (°C)

As shown above, the average temperature is 26.567°C, the inlet-outlet temperature difference is 3.5°C, and the center-ambient temperature difference is 3.7°C.