Specifications

C E N T A U R U S P R I M E

avoid ground-loops). This is a two-wire trunk, so it does not matter if you land the

field trunk wires on TX+/TX-, or on RX+/RX-. Just make sure the polarity is right!

Picture 1.2, Gateway Overview and Identification

Channel A, B, C, & D

Connecting to the Modbus Master

Connecting to the Modbus Master is done one of two ways:

(1) Ethernet:

If you have ordered the Trane-485 Gateway as the standard Modbus/IP configuration,

then it is simple: You plug in an 8-pin Category 5 or Category 6 cable into the

Ethernet connection on the top right-hand corner of the PC. You must set the IP

address of the Gateway to a static, fixed address, on the segment that you are in. This

is done with the CONFIG.TXT file, described in the next chapter.

(2) Serial Link:

If you have ordered the Trane-485 Gateway with the Modbus/RTU protocol option,

then the Modbus connection is made with the CS485 line driver included in the

Gateway cabinet, if the product has been ordered with a Modbus-RTU front-end. The

CS485 line driver is an RS-232 to RS-485 interface converter. It allows an RS-232