Show Latch Command

This command displays information about the configuration of any encoder position latches and pending latch events.

Show Latch [ -all ]

Prerequisites

None

Parameters

-all

An optional switch keyword that specifies that additional latch debug information is to be displayed for each latch event.

Remarks

This command displays information about the configuration of any encoder position latches, statistics on latch events, and data regarding pending latch events. Pending events are latches that have been triggered and captured by the system but have not been handled by a GPL program.

The output begins with the configuration display:
Local hardware latches:   hlatch
Defined latches:
  Type        Signal       Count
  type        signal           n
  type        signal           n
where

hlatch is the number of hardware latches available on this controller.
type is the latch type, either "hard" or "soft"
signal is the number of the I/O signal that triggers the latch
count is the number of events that have occurred for this signal.

The configuration data is followed by statistics and error counts. Only statistics and counts that are non-zero are displayed.

Label

Description

Local latch events

Total number of latch events detected by the local controller.

Queued latch events

Total number of latch events queued by the local controller. Will include events from remote servo network controllers.

Unmapped latch events

Number of latch events not assigned to any signal. Should never happen.

Position read failed

Number of latch events that could not be associated with an axis position. Indicates the controller is overloaded by too many latches occurring in rapid succession.

Input FIFO overflow

Number of latch events that were dropped because the software could not process them quickly enough. Indicates the controller is overloaded by too many latches occurring in rapid succession.

Output FIFO overflow

Number of latch events that were dropped because the latch event FIFO was full. Either DataID 16101 is too small, or the GPL program is not dequeuing events quickly enough.

Input signal overrun

Number of latch events that were missed because they occurred too quickly for the hardware to handle them.

Memory allocation failure

Number of latch events dropped because there was no free memory available.

Finally, the list of pending queued latch events are displayed. These events have been detected and queue by the system but have not been read by any GPL program. Each line contains the following information:

Label

Description

Robot

The number of the robot associated with this event.

Signal

The signal number associated with this event.

Timestamp

The time when this event occurred, in seconds, measured since the controller was first booted. This time was automatically saved by sampling the property latch_object.Timestamp(1).

Latched encoder counts

The encoder reading for each of the robot’s axes when the latch occurred.

If the -all switch was specified, three additional unlabeled columns (that are used for system debugging) are inserted between the Timestamp and Latched encoder counts columns. These columns are:

Description

column 1

The latched internal timer value when the latch event occurred, as a hex number.

column 2

The internal timer value with the latch event was serviced by the latch software.

column 3

The internal hardware latch control register when the latch event was serviced by the latch software.

Label	Description
Local latch events	Total number of latch events detected by the local controller.
Queued latch events	Total number of latch events queued by the local controller. Will include events from remote servo network controllers.
Unmapped latch events	Number of latch events not assigned to any signal. Should never happen.
Position read failed	Number of latch events that could not be associated with an axis position. Indicates the controller is overloaded by too many latches occurring in rapid succession.
Input FIFO overflow	Number of latch events that were dropped because the software could not process them quickly enough. Indicates the controller is overloaded by too many latches occurring in rapid succession.
Output FIFO overflow	Number of latch events that were dropped because the latch event FIFO was full. Either DataID 16101 is too small, or the GPL program is not dequeuing events quickly enough.
Input signal overrun	Number of latch events that were missed because they occurred too quickly for the hardware to handle them.
Memory allocation failure	Number of latch events dropped because there was no free memory available.

Label	Description
Robot	The number of the robot associated with this event.
Signal	The signal number associated with this event.
Timestamp	The time when this event occurred, in seconds, measured since the controller was first booted. This time was automatically saved by sampling the property latch_object.Timestamp(1).
Latched encoder counts	The encoder reading for each of the robot’s axes when the latch occurred.

	Description
column 1	The latched internal timer value when the latch event occurred, as a hex number.
column 2	The internal timer value with the latch event was serviced by the latch software.
column 3	The internal hardware latch control register when the latch event was serviced by the latch software.

Examples

GPL: show latch
 
Local hardware latches: 2

Defined latches:

  Type        Signal       Count

  Hard         10001           2

  Hard        -10001           2

Local latch events             4

Queued latch events            4

Robot    Signal      Timestamp     Latched encoder counts

    1     10001     566.632602  0.000   1.000  -1.000    0.000

    1    -10001     568.380421  0.000   1.000  -1.000    0.000

    1     10001     570.330562  0.000   1.000  -1.000    0.000

    1    -10001     571.358295  0.000   1.000  -1.000    0.000