Siemens SIMATIC PANEL PC 877 Operating Instructions Manual page 220

Detailed descriptions
17.2 Bus board
Pin No.
C1
C2
C3
C4
C5
C6
C7
C8
C9
C10
C11
C12
C13
C14
C15
C16
C17
C18
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
Abbreviation Type*
-SBHE O
LA 23 I/O
LA 22 I/O
LA 21 I/O
LA 20 I/O
LA 19 I/O
LA 18 I/O
LA 17 I/O
-MEMR I/O
-MEMW I/O
SD 08 I/O
SD 09 I/O
SD 10 I/O
SD 11 I/O
SD 12 I/O
SD 13 I/O
SD 14 I/O
SD 15 I/O
Pin No. Abbreviation
D1 -MEMCS16
D2 -IOCS16
D3 IRQ 10
D4 IRQ 11
D5 IRQ 12
D6 IRQ 13
D7 IRQ 14
D8 -DACK0
D9 DRQ 0
D10 -DACK5
D11 DRQ 5
D12 -DACK6
D13 DRQ 6
D14 -DACK7
D15 DRQ 7
D16 + 5V
D17 -MASTER
D18 0 V
Operating instructions, Release 07/2006, A5E00877780-01
Type
I
I
I
I
I
I
I
O
I
O
I
O
I
O
I
VCC
I
GND
SIMATIC Panel PC 877