Siemens SIMATIC S5-115F - B.6 Legend for Connector Pin Assignment

Slot Assignments S5-115F Manual
B.6 Legend for Connector Pin Assignment
Supply voltage for all modules
GND (0 V reference potential) for +5 V
3.4 V battery voltage for RAM backup
Reset pulse for all modules
Reset pulse request (triggers a reset pulse or extends it)
Battery failure; the signal is generated if the battery is not
plugged in or if it is flat.
Power failure; the signal is generated shortly before the supply
voltage fails.
I/Os not ready; the signal is generated if the power supply in the
expansion unit fails.
Data security; the signal is generated with a delay after NAU and,
in the case of some modules, switches the battery-backed RAM to
standby hardware.
Command output disable; the signal is generated when the CPU
stops. The signal disables digital outputs.
Memory Read; the signal is generated at every Read access.
Memory Write; the signal is generated at every Write access.
Ready; acknowledgement signal for MRD or MWR access
Memory I/O select; the signal is generated at every I/O access.
Interface free; the central controller is operated without an
interface module; a terminating resistor must be plugged into the
IM slot.
Interface module plugged in
Interrupt A, B; hardware interrupt signals from intelligent I/O
modules
Process interrupt; hardware interrupt signal from a digital I/O
module
S5 bus enable for the intelligent closed-loop control module
S5 bus access by the intelligent closed-loop control module
Enabling lines for the I/O modules
Address bus
Data bus
+5V
M
U
BATT
RESET
RESETA
BAU
NAU
PEU
DSI
BASP
MRD
MWR
RDY
PESP
ASF
ASG
IRA, IRB
PRAL
HOLDA1, 2, 3
HOLD
F0 to 8
ADB0 to 15
DB0 to 7
B-10 EWA 4NEB 811 6148-02