Topic: DMD0404
BRX Table Driven Outputs
This dialog selects which of the available High-Speed discrete outputs (either the on-board high speed discrete outputs or the outputs on a BX-HSIO1, BX-HSIO2 module) will be used as Table Driven Outputs when they are placed under the control of a Preset Table or a PLS Table.
This dialog does not load a Preset Table or a PLS table, it only selects which outputs will be used as Table Driven Outputs. The Load Preset Table (TDOPreset) and Load Programmable Limit Switch Table (TDOPLS) instructions actually load a table and bind the specified discrete output to that table. Once a Preset Table or PLC table has control of a discrete output, is will relinquish that control of that discrete output only after a Deconfigure Table Driven Output instruction has been executed for that discrete output.
Device Name is a name given to this High-Speed I/O Preset Table function. This name will also be used as the name of the structure you will use to interact with this Preset Table in the ladder logic project. The device name can be 1 to 16 characters in length and consist of any combination of alphanumeric characters and underscores ('_', 'a-z', 'A-Z', 0-9), no spaces or punctuation marks are allowed, and must begin with a letter or an underscore.
Heap Item is the structure that is associated with this device. This structure is automatically created when the Table Driven Output itself is created.
Function Output selects which of the unused High-Speed I/O outputs to use as the Table Driven Output. As the outputs are selected you will see one of the following text appear to the right of a selection:
**CONFLICT** indicates the currently selected output is already being used by a Table Driven Output.
*Selected* indicates the currently selected output.
Pulse Output # indicates the output is already being used by an BRX Pulse Output / Axis.
PWM # indicates the output is already being used as a Pulse Width Modulated Output.
Table # indicates the output is already being used as a Table Driven Output.
After the High-Speed I/O discrete output has been configured for use as a Table Driven Output, it is controlled using a Preset Table or a PLS Table as described below:
Preset Tables
A TDOPreset - Load Preset Table for Table Driven Output instruction contain a series of steps that are processed in the order they appear in the table. These steps compare the current count value of the specified Master Register to the Preset Count in the Step, and when the count values match the step's action is preformed on the selected discrete output and the next step in the table becomes the active step. Each Preset Table can have up to 64 steps. Each Preset Table compares the count value of one High-Speed I/O input and can drive one High-Speed I/O discrete output.
Once a Preset Table has been enabled for a Table Driven Output it will continue to control that output even if the input logic is no longer ON. Use the Deconfigure Table Driven Output (TDODECFG) instruction to stop the Preset table from controlling the Table Driven Output.
Programmable Limit Switch
A TDOPLS - Load Programmable Limit Switch Table for Table Driven Output instruction contains a table with a series of start and stop positions similar to the cams on a shaft. These cam positions are compared to the current count value of the specified Master Register. When the count value falls between any of the positions in the table the discrete output is turned ON or OFF as specified in the table. Each table can have up to 64 cam positions. Each PLS table compares the count value of one High-Speed I/O input and can drive one High-Speed I/O discrete output.
Once a PLS Table has been enabled for a Table Driven Output it will continue to control that output even if the input logic is no longer ON. Use the Deconfigure Table Driven Output (TDODECFG) instruction to stop the PLS table from controlling the Table Driven Output.
Deconfigure Table Driven Output
Once a TDOPLS - Programmable Limit Switch on Table Drive Output or TDOPreset - Run Preset Table on Table Drive Output has been enabled for a Table Driven Output, it will continue to control that output even if the input logic is no longer ON. Use the Deconfigure Table Driven Output (TDODECFG) instruction to stop the Preset table or PLS table from controlling the Table Driven Output.
See Also:
BX-HSIO1 / BX-HSIO2 High-Speed I/O Modules
BRX Pulse Width Modulated Outputs