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ControlLogix 7252 LDT Interface Manual
Revision 1.5
Wiring Notes
•
Use the information provided by the transducer’s manufacture to determine the type and maximum length of
cable that should be used to connect the sensor to the 7252 module.
•
When plugged into the 7252 module, pin 1 is located in the upper right hand corner.
•
Ex24Vdc (pins 2 and 20) are internally connected together.
•
GND1/2/3/4 (pins 3, 4, 21 and 22) are internally connected together and must be connected to the external
+24Vdc supply’s common.
•
The 7252 module uses the ex24Vdc supply to power the isolation circuitry and to ge5Vdc user
power (pins 23 and 24). These two pins, which are internally connected together, can be used to power sensors
requiring less than 500 mA of current.
•
Earth Grounds 1 through 4 (pins 1, 13, 14 and 19) are internally connected together and are connected to the
ControlLogix rack structure. The cable shields of the sensor’s cable should be connected to these terminals.
•
Transducer signals are generally low voltage, low power signals. If you are using A-B guidelines for cabling
installation, treat the transducer cable as a Category 2 cable. It can be installed in conduit along with other low
power cabling such as communication cables and low power ac/dc I/O lines. It cannot be installed in conduit
with ac power lines or high power ac/dc I/O lines.
•
Like all signal and communication cable, the transducer cable should be shielded. These shields must be
grounded only at one end of the cable. Because the rack cabinet is typically better grounded than the machine,
AMCI recommends that the cable shields be terminated at the 7252 module. However, if your cable shield is
attached to the sensor’s housing, and the sensor is grounded through its mounting, you must not connect the
cable shields to the 7252 module because this will create a ground loop.
•
If a junction must be made in the signal cable, treat the shield as a signal-carrying conductor. Do not connect
the shield to ground at any junction box or the encoder/sensor.
•
If the signal cable must cross power feed lines, it should do so at right angles.
•
Route the cable at least five feet from high voltage enclosures, or sources of RF radiation.
Voltage
Regulator
External Power
Supply
+24Vdc, pins 2 or 20 (connected together internally)
GND, pins 3,4,21,22)
+5Vdc out, pins 23, 24
+5Vdc
Optical isolation
+input data pins 9 or 10
-input, pins 11 or 12
7252 module
