Greer Company
Greer Company
Greer Company
Greer Company
Crane Systems
1918 EAST GLENWOOD PLACE, SANTA ANA, CA 92705
Tel: (714) 259 9702 Fax: (714) 259 7626
MicroGuard
424 Operation/Troubleshooting Manual Horizontal Display Hydraulic Cranes
42 of 52
W424103 REV A 02/13/01
ANTI TWO
ANTI TWO
ANTI TWO
ANTI TWO----BLOCK LOGIC LEVELS
BLOCK LOGIC LEVELS
BLOCK LOGIC LEVELS
BLOCK LOGIC LEVELS
The signal from the ATB switches at the boom and fly
tips is a switched ground. The ground signal is sourced
in the computer at the
0 volt terminal
of the digital input
group.
When there is no ATB alarm, the switches at the boom
head are
closed
allowing the ground to be returned to the
computer at the
ATBIN
terminal.
When there is a two-block condition the appropriate ATB
switch will go to the
open
position thereby removing the
ground from ATBIN and causing ATB Alarm and
Function Disconnect.
The ATB alarm and Function Disconnects are controlled
separately by the ATB board in the computer.
The ATB board, located in the computer box:
•
Operates the function disconnects by controlling the
coil of RL2, ATB relay, at D OUT 1.
•
Operates the audible alarm and on screen message
by controlling the logic level at DIN13.
The logic levels are as follows:
NO ALARM
ATB ALARM
ATB SWITCH
CLOSED
OPEN
ATB IN
LOW
0.2 VOLT
HIGH
5 VOLT
D OUT 1
LOW
0.2 VOLT
HIGH
5 VOLT
D IN 13
HIGH
12 VOLT
LOW
0.2 VOLT
The voltage levels are approximations and small
variations are to be expected.
D O U T1
A TBIN
A TB BO A RD
RL2
A 2B
RL1
LO A D
D IN 13
D O U T1
C O N TRO LS TH E A 2B
RELA Y RL2
N O A 2B = LO W , 0.2V O LT
A LA RM = H IG H , 5V O LT
D IN 13
C O N TRO LS TH E
A U BIBLE A LA RM A N D
O N SC REEN M ESSA G E.
N O A 2B = H IG H 12V O LT
A LA RM = LO W 0.2V O LT
A TBIN
N O A 2B = LO W
O .2V O LT
A LA RM = H IG H
5V O LT
0V