Global Interlock Controller Display

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The GIC display shows the status of the GuardLogix controllers as well as the status of the main permissive signals that are controller by the GIS. The six controllers that make up the GIS are shown in columns.

Two GOTO buttons, as well as standard navigation buttons are present along the bottom of the screen. The Home button can be used to open the Main Display. The Return button will close the graphic display and reopen the display that was previously open. Previous and Next will advance you through the GIC Displays.

Processor Name

The first row displays the name of the controller. These show which controller is associated with which subsystem. The information is read from the controller itself.

Is Present?

The second row displays the status of communications from the HMI to the controller. The standard indication should be “is present.” This indicates that the Logix controller is on-line and contains a program. If not check power, communications path.

Status

The third row reports the status of the controller. Generally, this will be “OK”. If the status is “Faulted” then the controller has encountered a major fault. For further troubleshooting, RSLogix will have to be connected to the controller and examine the controller properties to determine the exact nature of the fault.

Mode

The fourth row displays the position of the key switch on the front panel of the controller and the mode that has been selected. Possible responses are “Run”, “Program”, “Remote Run”, or “Remote Program”. The system should normally be in “Run” or “Remote Run”. If “Remote Program” is displayed, RSLogix will have to connect to the controller and switch controller to run mode. If “Program” is selected then the key switch will have to be changed to either “Run” or “Remote.”

If the mode selected is “Remote Run” this indicator will display as yellow. This indicates that a remote user has the ability to alter the program.

Safety Lock State

The fifth indicates the status of the controller’s safety lock. Normally this should be Safety Locked. If it is not, determine why it is not before proceeding with operations.

Unlocked indicates that the safety code is not protected from modification. A user can connect and modify programs, force input/outputs, manipulate the safety signature, and various other functions.

Safety Signature

The sixth row displays the safety signature (or in the case of an L8xES processor just part of the safety signature). The background is yellow if the current safety signature does not match the safety signature that was last stored in the HMI. This doesn’t mean it is the wrong signature, just the safety signature has been changed recently or the proper safety signature was not stored.

Master Clock Accuracy

The seventh row displays the value of the accuracy of the local clock to parent clock. This is not the offset to the grandmaster clock but rather an estimate of the accuracy of grandmaster clock.

I/O Status

The eighth row indicates if communications between the controller and its configured I/O is working properly. There are four possible states: “OK”, “Partial”, “None”, and “Not configured.” Anything other than “OK” indicates that troubleshooting should take place to understand the reason for the loss of communications. A partial loss of communications should not adversely affect safety, although it will likely result in some loss of functionality.

Safety Instruction Status

The ninth row displays that status of safety instructions associated with that controller. Normally, no safety instruction faults should be present. However, safety instruction faults should not adversely affect safety, although it will likely result is some loss of functionality. First step to recovery is to attempt a GIS reset. This will clear many safety instruction faults but not all of them.

This indicator also serves as a GOTO button that will open the appropriate Diagnostic Page(s) for the associated controller.

E-Stop Status

The tenth row displays the status of the emergency stop system associated with that controller. Normally, this should be “OK”. If an E-Stop has been trigger it must be corrected before any operations can take place. This indicator as serves as a GOTO button that will take the user to the status display for that subsystem’s emergency stop devices.

Axis Status

The rest of the indicators on this page display the status of one of the major components of the telescope such as Coudé Azimuth Axis, Telescope Altitude Axis, Telescope Azimuth Axis, Enclosure Altitude Axis, Enclosure Azimuth Axis, and the Aperture Cover. These indicators function as navigation buttons as well. In addition there are indicators for the Gregorian Optical System (GOS) and Instrument permissive signals.