ioPAC 8500 Hardware
Installation
2-10
RJ45 Ethernet Connector
The ideal maximum cable length of a 10/100BaseT connection is 100 m (350 feet), but the actual limit could be
longer or shorter depending on the amount of electrical noise in the environment. To minimize the amount of
noise, Ethernet cables should not run parallel to power cables or other types of cables that generate electrical
noise.
The following diagram and table shows the pin connections for the RJ45 Ethernet connector:
RJ45 Connector Pin Assignment
Contact Media Direct Interface Signal
1
Tx + (transmit)
2
Tx - (transmit)
3
Rx + (receive)
4
Not used
5
Not used
6
Rx - (receive)
7
Not used
8
Not used
M12 Ethernet Connector
The ioPAC 8500 has two 10/100BaseT(X) Ethernet ports that use 4-pin shielded M12 connectors with D coding.
The 10/100T(X) ports located on the front panel of ioPAC 8500 are used to connect to Ethernet-enabled devices.
Most users configure these ports for Auto MDI/MDI-X mode, in which case the port’s pinouts are adjusted
automatically depending on the type of Ethernet cable used (straight-through or cross-over), and the type of
device (NIC-type or HUB/Switch-type) connected to the port.
•
The Auto MDI/MDI-X function (M12 connector) allows users to connect the ioPAC 8500’s 10/100BaseTX
ports to any kind of Ethernet device, without needing to pay attention to the type of Ethernet cable being
used for the connection. This means that you can use either a straight-through cable or cross-over cable to
connect the ioPAC 8500 to Ethernet devices.
The following diagram and table shows the pin connections for the M12 Ethernet connector:
M12 Ethernet Connector Pin Assignments
Male Wire-Color
Bus
Reference
1
Orange
(+)
B
2
Not used
n.c
–
3
–
Shield
S
4
Blue
-1
A
In what follows, we give pinouts for both MDI (NIC-type) ports and MDI-X (HUB/Switch-type) ports. We also
give cable wiring diagrams for straight-through and cross-over Ethernet cables.
