GE GFK-0787B user manual Redundancy Modes for Output Blocks, GMR Mode

3

Redundancy Modes for Output Blocks

There are three separate configuration processes for a GMR system:

HGMR configuration, which supplies parameters used by the GMR system software.

HPLC configuration, which is performed as usual for a Series 90-70 PLC system using the Logicmaster 90 software.

HGenius block configuration, which sets up the operating characteristics of the blocks themselves.

It is during Genius block configuration that the redundancy mode of blocks is selected. This is particularly relevant to the operation of output blocks. The four possible choices for redundancy mode are:

A.GMR

B.Hot Standby PLC Redundancy

C.Duplex PLC Redundancy

D.No PLC Redundancy

Blocks in an output group must be set up for GMR mode. This changes the operating characteristics of the block as described.

Individual output blocks (or combination I/O blocks) can be set to any of the latter three modes (above). Block operation in these modes is described in the Genius I/O System User's Manual and in the Genius Discrete and Analog Blocks User's Manual.

If an individual block is configured for Hot Standby redundancy mode, it can be included in the GMR configuration as a Non-voted Discrete Group.

Blocks that are set up for Duplex PLC redundancy or no redundancy are not autotested. They operate in the same manner as Duplex blocks in a non-GMR system.

GMR Mode

Configuring a block for GMR mode changes its operating characteristics as described below.

HGMR mode supports non-redundant outputs with or without pulse test, and redundant outputs with or without output autotest.

HTo prevent false Failed Switch diagnostics during switching transitions, detection of Failed Switches is delayed for one second.

HFor the 16-circuit DC block, detection of No-load faults is delayed for one second. This prevents No-load faults being falsely reported during switching transitions.

HOperation of Block OK LED is modified. For the 16-circuit DC block, the Unit OK LED does not indicate No-load faults when the block is in GMR mode. This is necessary, since blocks may share output loads.

HModified fault reporting. In GMR mode, blocks automatically report faults to bus controllers at serial bus addresses 29, 30, and 31.

GFK-0787B Chapter 3 Output Subsystem 3-9