Builder

Setup of Steps in Accord Builder

All Programs in Accord contain Steps. A program may be configured for any number of Steps, and a single Step may be repeated any number of times in the Step Order. In the properties for the Program the top option is to declare the program as a Single Step or Background program which is always running, or as a program with many steps.

Each Program has a Startup Step which is always processed when a start command for the Program is received and processed. The Startup Step only contains Alarms. The remaining Steps may contain Alarms, Operations and Automatic Activations as well as Step Transitions.

This section outlines the configuration of items in a Step.

Inserting a Step:

A Step is inserted into the Step holder of the Program by right-click on the Steps holder or by dragging the Step icon into the Steps Holder.

A Step may also be copied from another Step (Right-Click, Copy and give new name) in the same program. The Step properties and activations are then configured.

A Step may be added to the program by dragging the Step icon (in red square) from the toolbox to the program Steps component holder.

Step Properties:

There is an initial tab field for Step Properties which contains the default step time, and descriptions for the Step.

Step Time Setpoint: Each step has an allocated time. Generally this time is used as a step duration, in which case the program will move to the next step (see step order) when the duration time has elapsed. Step Time may be used as a watch-dog timer in an Alarm.Step time counts down when Program is not in Hold or TimeHold.

Short Description:  This is a basic description which will appear in the FDS and other documentation.

Long Description: A fuller description can be entered here, which will also be included in the documentation.

Operator Selection Notes: Notes which will be included in the FDS Document. The notes entered here would guide the operator in preparation for the step or in the event of errors or unusual events.

Alarms in the Step:

This tab allows Alarms to be enabled in a Step. An Alarm may be configured at any time and subsequently added to Steps. The addition of an Alarm to a Step means that the Alarm will be monitored while the program is processing the Step.

An Alarm is enabled in a step by selecting it and adding it to the “Alarms enabled for this Step”. These Alarms will be monitored while the step is active.

An Alarm may be added for monitoring to multiple steps in a program. If an alarm is not added to a step then is will not be monitored while that step is active.

An Alarm may be removed from a step also by selecting the alarm in the right hand box “Alarms Enabled for this step” box and clicking on the remove button.

The system automatically assigns unit based alarms (Unit Selected and Unit Maintenance) to each program for each unit that is added to the Equipment Unit component holder. These alarms are automatically assigned to Step 0 – Pre Start Checking. These alarms may be added to other steps also and may be removed from any step.

Operations in the Step:

This tab allows Operations to be enabled in a Step. An Operation may be configured at any time and subsequently added to Steps. The addition of an Operation to a Step means that the Operation will be processed while the program is processing the Step.

Available Operations are already configured in the program. The Operation is enabled for the step by adding it to the “Operations enabled for this step” area.

A Operation may be enabled for multiple steps in a program. If an Operation is not enabled for a step then is will not be executed while that step is active.

A Operation may be removed from a step also by selecting the Operation in the right hand box “Operations enabled for this step” box and clicking on the remove button.

Activations in the Step:

Required Digital Devices (valves, motors, digital outputs) may be activated in a step. Only Devices in Units that have been added to the Program Equipment are available for Automatic Activation. The PLC program will automatically monitor for all device errors in Equipment Units of devices being activated.

This show the list of Device Activations in a Step.

The devices may be activated in one of three ways:

  1. Always during the step
  2. Pulsed during the step, according to the pulse setpoint and cycle times.
  3. Activated conditionally on one of the following;
    • Condition
    • Combined condition
    • Alarm
    • Digital input
    • Analog High High Alarm
    • Analog High Alarm
    • Analog Low Alarm
    • Analog Low Low Alarm
    • Step time
    • Valves Activated / Deactivated
    • Motors Activated / Deactivated
    • Digital Output Activated / Deactivated
    • Valve Alarm
    • Motor Alarm
    • Analog Input WireBreak

The above items can be used for a true or false state where appropriate.

The activations tab shows step activations, which may be accessed using the Edit Activations button. List of Activations for a device are also available in the panel for Valve Motor or Digital Output.

Available Devices are listed in the top panel and Current Activation Devices are in the lower panel. Devices are added to Current Activations list  by selecting the Device in the top panel and then selecting the Activation On enabler. If the device is to be activated On Condition then the Enabler Type and Item are selected from the Drop Down list. The Device is then added to the Activations then by clicking on Add Activation button.

An Activation can be removed from the Current Activations list by clicking on the Device and clicking on the Remove button.

Step Transitons:

This tab allows the Normal, Alternative and External Step Transitions to be configured,

External Step Transition means that there is not process Step On, the Step is to be ended by an Operation or by HMI Command.

Normal Step Transition is the transition to the next step in the Step Order, and External Transition is a transition to a nominated step.

Both Normal and Alternative transitions are configured using the Drop-Down areas. The External Step On also has a selection for the target Step.

If External Transition is selected then Normal and Alternative are deselected or disabled.

For Normal and Alternative transitions the following may be used

  • Condition
  • Combined condition
  • Decision
  • Digital Input
  • Analog High High Alarm
  • Analog High Alarm
  • Analog Low Alarm
  • Analog Low Low Alarm
  • Step time
  • Valves Activated / Deactivated
  • Motors Activated / Deactivated
  • Digital Output Activated / Deactivated
  • Valve Alarm
  • Motor Alarm

True or False stares for the above are selectable.