GE GFK-0787B user manual Programming for I/O Shutdown, Enabling I/O Point Faults

7

I/O Point Faults

The GMR system can optionally use the standard Series 90-70 I/O Point Fault references.

The I/O Point Faults feature allocates a bit reference for each potential discrete point fault and a byte reference for each potential analog point fault.

Note that space for these references is taken from the space available for the application logic.

WithI/OPoint Faults enabled, when a fault occurs the fault reference (IO_FLT) is set.

The [FAULT] and [NOFLR] contacts can be used to access the point fault.

Point fault data is written to the references at the start of each CPU sweep, so they always contain the most recent data.

Enabling I/O Point Faults

The use of I/O point faults requires the following setup during Logicmaster 90 configuration:

A.During CPU configuration, select Memory Allocation and Point Fault Enable (F4) from the CPU Configuration menu.

B.Change the Point Fault Reference setting from DISABLED to ENABLED.

Programming for I/O Shutdown

When the GMR system diagnoses a discrete I/O fault, it logs the appropriate faults in its fault tables and set the appropriate fault contacts. For certain types of discrete I/O faults, the system allows a predefined amount of time for the problem which has caused the fault to be repaired. If it is not rectified within this period of time, an I/O shutdown of the I/O which corresponds to the block(s) occurs, unless I/O shutdown is disabled by the cancel I/O Shutdown control bit (%M12265). I/O shutdown is defined as setting the affected I/O to its safe state. For more information about I/O Shutdown, please refer to page 4-18.

To be aware of a pending I/O Shutdown, monitor Status Bit %M12244 (IO_SD).

To completely prevent an I/O Shut Down from occurring set Control Bit %M12265 (SD_CAN).

7-20	GeniustModular Redundancy Flexible Triple Modular Redundant (TMR) System	GFK-0787B
	User's Manual ± March 1995