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SMD23E2 and SMD24E2 User’s Manual
I
NSTALLING
THE
SMD23E2
OR
SMD24E2
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1.7 Input Wiring (continued)
1.7.1 Cable Shields
Because they are low power signals, cabling from the sensor to the SMD23E2 or SMD24E2 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 SMD23E2 or SMD24E2.
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 SMD23E2 and
SMD24E2 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 SMD23E2 or SMD24E2 input will be reversed. The SMD23E2 or
SMD24E2 input is off when the sensor is active. You can set the logic state of the input when you configure
the unit.
1.8 Network Connectors
Figure T1.6 shows the Ethernet connector pinout when viewed from the back of the SMD23E2 or SMD24E2.
The Ethernet ports on the units are an “auto-sense” ports that will automatically switch between 10baseT and
100baseT depending on the network equipment they are attached to. The ports also have “auto switch” capabil-
ity. This means that a standard cable can be used when connecting the SMD23E2 or SMD24E2 to any device,
including a personal computer.
Figure T1.6 M12 Ethernet Connector Pinout
The connector is a standard female four pin D-coded M12 connector that is rated to IP67 when the mate is
properly attached.
The SMD23E2 and SMD24E2 units have two ethernet ports. In non-redundant applications, either port can be
used to attach the unit to the network.
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
Pin 1: +Tx
Pin 2: +Rx
Pin 4: –Rx
Pin 3: –Tx
ETHERNET
Ports 1 & 2