3 system/sm-bus – BECKHOFF CB4055 User Manual
Page 17
System/SM-Bus
Chapter: Connectors
Beckhoff New Automation Technology CB4055
page 17
3.3 System/SM-Bus
Both SM-Bus signals, and signals for PS/2 keyboard, PS/2 mouse and speaker are provided through a
2x9pin connector (FCI 98424-G52-18LF, mating connector e.g. FCI 90311-018LF). For the #PSON
signal, please refer to the cautionary note in the chapter "Power Supply" (p. 16).
Pinout 2x9pin connector:
Description
Name
Pin
Name
Description
speaker to 5V
SPEAKER
1
10
GND
ground
reset to ground
RSTBTN#
2
11
N/C
reserved
keyboard data
KDAT
3
12
KCLK
keyboard clock
mouse data
MDAT
4
13
MCLK
mouse clock
battery
BATT
5
14
VCC
5 volt supply
power supply on
PS-ON#
6
15
SMBCLK
SMB clock
standby supply 3.3V
S3.3V
7
16
SMBDAT
SMB data
power button
PWRBTN#
8
17
SMBALERT# SMB alert
ground
GND
9
18
3.3V
3.3 volt supply