4 Firmware Drive Functions
4.12 Terminals
4-148
Figs. 4-19 and 4-20 show the system response to 24 V ON and OFF for a con-
figuration with and without shut-off valve.
Chronological sequence after connection of 24 V with shutoff valve
Power enable and velocity controller commands issued, setpoint > 0
24 V supply
24 V missing
message
Switch for servo
closed
solenoid valve
open
supply
Valve spool
zero
position
Fail-safe
Switches
closed
Shutoff valve
open
Shutoff valve
open
closed
Status bit
power enable
Status bit
Velocity
controller enable
Effective
velocity
setpoint
Fig. 4-19
Chronological sequence after connection of 24 V supply, with shut-off valve
Chronological sequence after connection of 24 V supply without shutoff valve
Power enable and velocity controller enable commands issued, setpoint > 0
24 V supply
24 V missing
message
Switch for servo
closed
solenoid valve
open
supply
Valve spool
zero
position
Fail-safe
Switches
closed
Shutoff valve
open
Shutoff valve
open
closed
Status bit
power enable
Status bit
Velocity
controller enable
Effective
velocity
setpoint
Fig. 4-20
Chronological sequence after connection of 24 V supply, without shut-off valve
SINUMERIK 840D/SIMODRIVE 611 digital, HLA Module (FBHLA) - 10.03 Edition
The valve supply is disconnected
only if bit 4 in MD 5530 is set to
Backup capacitor maintains
24 V for valve electronics
Power enable delay
Output value enable
delay
Power enable delay MD 5532
No shutoff valve connected
Output value delay MD 5531
Siemens AG, 2003. All rights reserved
02.99
10.03