Serial / Ethernet / Power Port Connection; Terminator Resistor Settings - ICPDAS GW-7238D User Manual

2.3.2 Serial / Ethernet / Power port connection

The GW-7238D provides one Ethernet and two serial interfaces for
users to use without any setting. It can communicate both Modbus TCP
and Modbus RTU to J1939 at the same time. In Modbus RTU
communication, it is recommended to use only one serial port (RS-232 or
RS-485) of the gateway at the same time.
The following figures describe the COM port, Ethernet and Power
connections.
Figure 2-8: COM / Ethernet / Power wire connection of GW-7238D
2.4

Terminator Resistor Settings

In order to minimize reflection effects on the CAN bus line, the CAN
bus lines have to be terminated at both ends by two terminal resistances.
Based on the ISO 11898-2 spec, each terminal resistance is 120 (or
between 108 ~132 ). The length related resistance should have 70
m /m. Users should check the resistances of their CAN bus, before they
install a new CAN network as figure 2-9.
GW-7238D J1939 to MBTCP Server / MBRTU Slave Gateway User's Manual (Ver.1.0, Nov. 2011) --- 12
Figure 2-9: Terminal Resistor