GE GFK-0787B user manual Initialize Data, GBC1 GBC2

6

Initialize Data

Next, select System to configure the Initialization Data.

'

Initialization data, as explained in the PLC Subsystem chapter of this book, is exchanged between PLCs during startup. It consists of data such as timers and counters and latched logic states.

It is important to be sure that the memory assignments you make here do not directly conflict with %R and %M memory used in the application program or required elsewhere by the GMR software. For more information about memory requirements for GMR, refer to the Programming chapter.

GBC_1 GBC_2

Enter the rack and slot location for the two bus controllers in the GMR group that will be exchanging global data. These can be any two bus controllers in the system, but they must be at the same rack and slot location in each PLC.

%M Start Ref If the PLCs will exchange %M data during startup, enter a starting reference and length in words. (If the PLCs will not exchange %M data at startup, enter 0 in the %M length field).

If another PLC is already online during initialization, the initializing PLC will place %M data received from that PLC into its own %M memory in this location. If both other PLCs are already online, the initializing PLC will place data from the PLC with the highest serial bus address into this %M location.

This %M location can be the same as the %M memory used in the application program. It is a temporary storage area that is only used at startup, to store a copy of another PLC's %M data.

It must begin on a byte boundary (multiple of 8, +1). By default, this starting reference is %M0001. The default length (next field) is 16.

%M Length Enter the length in words for the %M temporary storage area. It should equal the quantity (in words) of %M memory used in the application program.

6-20	GeniustModular Redundancy Flexible Triple Modular Redundant (TMR) System	GFK-0787B
	User's Manual ± March 1995