Logic interface item
Normal status output:
Type
Open collector transistor plus pull up resistor.
Refer to
Figure: Interface circuits for nEXT
turbo pump controllers on page 29
.
< Normal speed (default 80%)
Off (2.2 k
W
internal pull up to 12 V d.c.)
³
Normal speed
On (< 0.8 V d.c. sinking 20 mA)
Current rating
20 mA to 0 V
Voltage rating
28.8 V d.c. maximum external pull up voltage
Fail status output:
Type
Open collector transistor plus pull up resistor.
Refer to
Figure: Interface circuits for nEXT
turbo pump controllers on page 29
.
Fail
Off (3.3 k
W
pull up to 12 V d.c.)
OK
On (< 0.1 V d.c. sinking 1.7 mA,
< 0.8 V d.c. sinking 20 mA)
Current rating
20 mA to 0 V
Voltage rating
28.8 V d.c. maximum external pull up voltage
* Mating half of connector not supplied.
Table 9
Logic interface connector pins
Pin
Number
Signal
Polarity Use
2
0 V Control reference
-
0 V reference for all control and status
signals below.
3
START / STOP control
input
-
Connect to Pin 2 to start pump
4
STANDBY control
input / Serial RX / RS485
A-
-
Connect to Pin 2 to enable standby
speed when serial enable is inactive
and RS485 / RS232 switch is in the
RS232 position.
5
Serial enable
-
Connect to Pin 2 to enable the serial
link
7
FAIL / Serial TX / RS485 B
+
-
Logic high when fail condition exists
and serial enable is inactive and
RS485 / RS232 switch is in the RS232
position.
9
Analogue output
Positive 0
‑
10 V output proportional to
measured output
10
Chassis / Screen
‑
Screen
12
Chassis / Screen
-
-
15
NORMAL status output
-
Logic low when the rotational speed of
the pump is at normal speed or above
the normal speed
Page 28
B85200880_D - Technical data
