Setup of Digital Output in Accord Builder
A Digital Output is a PLC output signal which does not have a corresponding feedback. Examples might be Lamps, or signals to other PLC’s.
Following insertion in a unit, a Digital Output is configured with settings that will determine its operation and its description in documentation. During insertion, the Digital Output is given a name and short description. These may be changed at any time.
There are three tabs in the Digital Output properties configuration section. The general setup is given in the Current Item section. Cross reference, Save and Close buttons are also provided.
Following insertion in a unit each Digital Output must be configured with settings that will determine its operation and its description in documentation. During insertion the Digital Output is given a name and short description. These may be changed at any time.
Each Digital Output is assigned 1 PLC Output. There are no Feedbacks.
Type: This sets the type as No Feedbacks.
Output: This is the PLC Output address for the device. This may be Electrical or Bus address
Note: Digital Output are understood to be “Command to Activate’ and no Command means Deactivation i.e. that loss of the PLC output signal will cause the Digital Output to turn off.
Delay On SP: This is the time, in seconds, that the motor automatic activation will be delayed by the device routine. This feature is used to avoid pressure issues.
Delay Off SP: This is the time, in seconds, that the motor automatic deactivation will be delayed by the device routine. This feature is used to allow stopping of the motor before closing valves to avoid line hammer and other pressure issues.
Pulse Cycle Time: This is the overall time of the motor pulsing cycle in seconds.
Pulse Time SP: This is the time, in seconds, that the motor will be pulsed for, during the pulse cycle.
State Text: This text is used to describe the On and Off states of the item in documents and controls. This is a free text field.
Remain Active during Program Hold: This enables the motor to stay On or Activated if the Program ( sequence) that has activated the item goes into Hold or Error state
Conditionally Activate with Pulse: This enables the motor to be pulsed according to a condition in the Program.
Enable Reserved for Automatic: This is to have the motor reserved for automatic only. When this is selected then Manual mode can only be selected with a specific additional override.
Manual Only: This option is used if the motor will not be controlled automatically, only controlled from HMI.
Short Description: A short one-line description for the Device.
Interlocks are conditions of devices and instruments that prevent a device from activating. This is to prevent damage to equipment or to material. For example, a pump may not run if a low level in a pipe exists to prevent the pump running dry, or two particular valves may not open together to prevent product mixing.
Interlocks are applicable to HMI manual activation as well as automatic activations.
Clicking on the Edit Interlocks button brings up the Interlocks Tab. There are two types of interlocks allowed. In the first section – the device will be Interlocked unless One item is True, and in the second section – the device will be Interlocked if Any item is True.
Both sections are considered always, – the Device will be interlocked on either section.
Interlocks are configured in same manner as for Digital Valves and Motors
The configured Activations for the Motor can be seen here, listed with the type of Activation and the program Step in which the Activation occurs. Activations can be removed from this panel by right-clicking on an Activation, to either remove an individual Activation or All Activations.
Activations are viewed in same manner as Digital Valves and Motors.
Card Setup Tab:
A PLC is composed of a CPU and I/O cards on racks, and in some cases communications processors, special function modules and bus based I/O.
Panel, Central Rack, Slot and Channel: These are all text input fields. Once a text is entered for a device or instrument, it then becomes available for other objects in the project. There is no validation on this information; the same combination of information could be entered for more than one device. This would be erroneous as each device must be unique, so care must be exercised in inputting the information. This can be filled in the IO Table in the Menu.
Type: The type of signal associated with the Digital Output is also described in this tab. The information stored in this area is used for documentation and does not comprise object data for PLC control.
The following aspects of the device may be filled in if required:
Symbol: This may be an asset number or any unique identifier which describes the object within the entire company. This could contain references to the plant, the area within the plant, the unit and the digital input name itself.
Part Number: This is the supplier reference for the item.
Type Description: This is a general description of the type of item. If a type is entered, then it becomes available to all other objects of the same type.
Long Description: This describes the object in more detail, if required.
Supplied By: Name of the supplier.
Notes: General Notes on the object. This may contain reference to maintenance manuals, maintenance history or location and type of spare parts.