Woodward AtlasPC, Hardware Manual

Page: 56 / 134

AtlasPC Digital Control, Vol. I Manual 85586V1
48 Woodward
A proximity probe may be used to sense very low speeds. With a proximity
probe, speed can be sensed down to 0.5 Hz. When interfacing to open collector
type proximity probes, a pull-up resistor is required between the supplied
proximity probe voltage and the proximity probe input to the SmartCore board.
Atlas
51
52
53
54
Active
Pickup
+V
Atlas
51
52
53
54
Active
Pickup
+V
PNP Type NPN Type
Jumper Jumper
Figure 6-4. Wiring Example–Proximity Probe to the SmartCore Board
Configuration Notes
•
Refer to Figures 6-3 and 6-4 for speed sensor wiring.
•
Each speed input channel can only accept one MPU or one proximity probe.
•
Proximity probe power is not provided.
•
Proximity probes only—External pull-up resistors are required when
interfacing to open collector type proximity probes.
•
If the proximity probe inputs are used, the corresponding MPU inputs must
be jumpered as shown.
Speed Sensor Input Software Configuration Limitations
•
(TxMxR)/60 must be < 25 000 Hz
T = gear teeth
M = (overspeed test limit setting x 1.2)
R = gear ratio
Analog Inputs
The analog inputs may be current or voltage type. If a current input is used, a
jumper is installed on the terminal block, and the software must be selected for
current. This allows the SmartCore card to use the applicable hardware
calibration values. If a voltage input is needed, the jumper must be removed, and
the software must be selected for voltage. See Figure 6-5 for jumper locations.
All Analog inputs may be used with two-wire ungrounded (loop powered)
transducers or isolated (self-powered) transducers. All Analog inputs have 10
Vdc of common mode rejection. If interfacing to a non-isolated device, which may
have the potential of reaching over 10 Vdc with respect to the control’s common,
the use of a loop isolator is recommended to break any return current paths,
which could produce erroneous readings.