Siemens PANEL PC 877 Sbhe MEMCS16, DACK0 Memr DRQ, Memw, DACK5, DACK6, DACK7, Master

Detailed descriptions 17.2 Bus board

Pin No.	Abbreviation	Type*	Pin No.	Abbreviation	Type
C1	-SBHE	O	D1	-MEMCS16	I
C2	LA 23	I/O	D2	-IOCS16	I
C3	LA 22	I/O	D3	IRQ 10	I
C4	LA 21	I/O	D4	IRQ 11	I
C5	LA 20	I/O	D5	IRQ 12	I
C6	LA 19	I/O	D6	IRQ 13	I
C7	LA 18	I/O	D7	IRQ 14	I
C8	LA 17	I/O	D8	-DACK0	O
C9	-MEMR	I/O	D9	DRQ 0	I
C10	-MEMW	I/O	D10	-DACK5	O
C11	SD 08	I/O	D11	DRQ 5	I
C12	SD 09	I/O	D12	-DACK6	O
C13	SD 10	I/O	D13	DRQ 6	I
C14	SD 11	I/O	D14	-DACK7	O
C15	SD 12	I/O	D15	DRQ 7	I
C16	SD 13	I/O	D16	+ 5V	VCC
C17	SD 14	I/O	D17	-MASTER	I
C18	SD 15	I/O	D18	0 V	GND

Under normal conditions, the signals -SBHE, LA17 - LA23, -MEMR and MEMW are operated as outputs (sending from the CPU). Only CPU modules which are suitable for use as a master CPU for system bus access send and receive these signals. A minus sign “-” in front of the signal name shows that the signal is LOW active.

17-28	SIMATIC Panel PC 877
	Operating instructions, Release 07/2006, A5E00877780-01