20
ICC
100BASE-TX. Mode B power transmission, therefore, requires the use of a full
4-pair Ethernet cable.
The gateway enumerates itself as a power level class 0 device (12.95W max.
indicated consumption). The use of PoE endspan (“PoE switch”) or midspan
(“power injector”) power sourcing equipment (PSE) provides for the ability to
power the gateway without the necessity of connecting a dedicated power supply
to the power supply terminal block.
5.3
RS-485 Port Electrical Interface
In order to ensure appropriate network conditions (signal voltage levels, etc.)
when using the gateway’s RS-485 port, some knowledge of the network interface
circuitry is required. Refer to Figure 2 for a simplified network schematic of the
RS-485 interface circuitry. The port has 4 terminals for four-wire communication.
For two-wire communication, connect a jumper wire between TB:1 (A / RXD+)
and TB:3 (Y / TXD+) and a wire between TB:2 (B / RXD-) and TB:4 (Z / TXD-).
Figure 2: RS-485 Interface Circuitry Schematic
