Burkert Type 8681 - Manual (Page 42)

42
AS Interface - Design
NOTE!
if all three solenoid valves are simultaneously controlled via the as interface, the electronics will
activate the valves sequentially with a 200 ms time delay to protect the as interface from overloads.
Please observe the notes on power requirement and maximum expansion stage of the AS interface
network contained in chapter
11.3. Number of Connectable Control Heads and Maximum Length of the
Bus Line and in the AS Interface Specifications, where applicable.
external Power Supply:
External power supply 19.2 V DC to 31.6 V DC
The power supply unit must include a secure disconnect in accordance
with IEC 364-4-41. It must conform to the SELV standard. The ground
potential may not have an earth connection.
Max. power consumption from external
power supply for
outputs (solenoid valves) -
without integrated current limiting ≤ 110 mA at 24 V DC
Max. power consumption from AS interface
for inputs and display ≤ 150 mA typ.
Integrated short-circuit protection
Please observe the notes on power requirement and maximum expansion stage of the AS interface
network contained in chapter
11.3. Number of Connectable Control Heads and Maximum Length of the
Bus Line and in the AS Interface Specifications, where applicable.
design aid 11.5.
Design aid for supply of the valves via the AS Interface Bus
power consumption of the electronics:
P
El
= 1.0 W or I
El
= 33 mA at 30.5 V
power consumption of a valve during activation (200 ms):
P
Valve-On
= 0.9 W or I
Valve-On
= 30 mA at 30.5 V
power consumption of a valve after reduction:
P
Valve
= 0.8 W or I
Valve
= 26 mA at 30.5 V
power consumption of an optical position report:
P
LED
= 1.0 W or I
LED
= 33 mA at 30.5 V
For the design of the maximum line length observe chapter 11.3. Number of Connectable Control Heads and
Maximum Length of the Bus Line.
Also, if several control head valves were to be opened simultaneously via the bus, the switch signal will be
sent staggered to the valves. Only
one valve will consume 0.9 W at any time.
english
Control Head Type 8681