Honeywell HC900 Benutzerhandbuch
Communications Installation - Connecting the HC900 Controller to Modbus device(s)
Revision 5
HC900 Hybrid Controller Installation and User Guide
105
9/03
Connecting the HC900 Controller to Modbus device(s)
RS-485 Modbus connections
Using the master and slave(s) RS-485 ports of the controller and other device(s), connect as shown.
Master
120 ohm
Slave 1
Slave 2
Slave n
. . .
120 ohm
TX/RX-
TX/RX+
TX/RX-
TX/RX+
TX/RX-
TX/RX+
Shield
Shield
. . .
. . .
. . .
120 ohm termination resistors required at master and last slave on the link.
TX/RX-
TX/RX+
Use HC Designer software to configure the controller’s RS-485 port as a master or slave.
RS-232 Modbus Connections
Connect to the RX, TX, and ground pins of the controller’s 9-pin RS-232 port. Table 17 (page 90)
identifies the pins. For connections on other device, refer to its product manual.
identifies the pins. For connections on other device, refer to its product manual.
For multiple devices on RS-232, use an approved RS232-to-RS485 converter.
Use HC Designer software to configure the controller’s RS-232 port as a master or slave.