AMCI SMD17K, User Manual

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SMD17K User Manual
I
NSTALLING THE
SMD17K
83
1.7 Input Wiring
Inputs 1 and 2 are single ended inputs that share the DC Common return pin. They accept 3.5 to 27 Vdc with-
out the need for an external current limiting resistor. Figure T1.6 below shows how to wire discrete DC sourc-
ing and sinking sensors to inputs 1 and 2 of the SMD17K. Colors in parentheses are the appropriate wire color
of the CNPL-5M cable.
Figure T1.6 Input Wiring
1.7.1 Cable Shields
Because they are low power signals, cabling from the sensor to the SMD17K should be done using a twisted
pair cable with an overall shield. The shield should be grounded at the end when the signal is generated,
which is the sensor end. If this is not practical, the shield should be grounded to the same ground bus as the
SMD17K.
1.7.2 Sinking Sensors Require a Pull Up Resistor
Sinking output sensors require an external pull up resistor because inputs 1 and 2 of the SMD17K units also
sink current. Table T1.1 below shows the values of pull up resistors that will allow the unit’s input to activate
along with the current that the sensor must be able to sink when it is active.
Table T1.3 Pull Up Resistor Values for DC Inputs
The logical states of the sensor and SMD17K input will be reversed. The SMD17K input is off when the sen-
sor is active. You can set the logic state of the input when you configure the unit.
Input
Voltage
Pull Up
Resistor
Sensor Current
When Active
5 Vdc 300 ohm 16.7 mA
12 Vdc 1.4 kilohm 8.6 mA
24 Vdc 3.8 kilohm 6.3 mA
Input1 or Input2
Input1 or Input2
DC Common
DC Common
+
+
+
+
–
(WHT or BLK)
(WHT or BLK)
–
5 to
24 Vdc
5 to
24 Vdc
PNP
Sourcing
Sensor
NPN
Sinking
Sensor
Out
Out
R
PULLUP
See 1.7.1
See 1.7.1
See 1.7.2
(BLU)
(BLU)