State Industries GFK-0827 manual CPU Architecture, Watchdog Timer

2

PRIMARY UNIT

P	C	B	R	G
S	P	T	C	B
	U	M	M	C
				31

Redundancy Communications Link

Redundancy Communications Link

CPU 780

		SECONDARY UNIT			a47002
P	C	B	R	G
S	P	T	C	B
	U	M	M	C
				30

Genius Bus

Figure 3. CPU 780 Locations in a Hot Standby CPU Redundancy System

The capacities for the CPU 780 are as listed in the following table.

Table 1. Capacities for Redundancy CPU, IC697CPU780

Speed		Input	Output	On-Board	Expansion Memory	Floating Point
(MHz)	Processor	Points	Points	UserMemory	(KBytes)	Math
16	80386DX	12288 [	12288 [	notavailable	128/256/512	Yes

[The total number of Input points and Output points on the model 780 CPU cannot exceed12288.

CPU Architecture

The CPU 780 has an 80386DX microprocessor as the main processing element, on-board memory, a dedicated VLSI processor for performing boolean operations and interfaces to a serial port and the system bus. The microprocessor provides all fundamental sweep and operation control, plus execution of non-boolean functions. Boolean functions are handled by a dedicated, VLSI, Boolean Coprocessor (BCP) designed by GE Fanuc.

Program and data memory on the CPU 780 is available by the attachment of an expansion memory board with either 128 Kbytes, 256 Kbytes or 512 Kbytes of battery-backed CMOS RAM, or 256 Kbytes with 256 Kbytes of non-volatile flash memory.

When the CPU board is in storage, disconnect the lithium battery if there is no application program stored in memory. If a program is stored in memory, do not disconnect the battery; otherwise the data will be lost.

Caution

If a LowBattery Warning occurs, replace the battery beforeremoving power from the rack. Otherwise there is the possibility that data will be corrupted or the program will be cleared from memory.

Watchdog Timer

The CPU provides a watchdog timer to catch certain failure conditions. The value of this timer is controlled by the user from the programmer. The valid range of the watchdog

14 Series 90-70 Hot Standby CPU Redundancy User's Guide ± December 1993 GFK-0827