Edwards nEXT730 - Page 43

B8J200880_E - Technical data
Page 42
Logic interface item
< Normal speed (default 80%)
Off (2.2 k pull up to 12 V d.c.)
 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.
Fail
Off (3.3 k 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.
Refer to the following table for Logic Interface connector pins for the electrical
connections.
Table 11 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 pump rotational speed
is at normal speed or above