Carrier RTU Open v5 Integration Manual page 17


Proper connection wiring

Wiring specifications are 18 - 28 AWG; twisted pair, and 50 feet (15.4 meters) maximum

Unique rotary address switches 1 – 99. If controllers have duplicate addresses, network communication can
be lost.
NOTES

If RX LED is solid, then the terminations are incorrect.

If the network has greater than 32 devices or exceeds 2,000 feet, a Repeater should be installed.

If a controller begins or ends a network segment, a terminating resistor may be needed.

The controller recognizes physical changes (DIP switches, rotary switches, and jumpers) upon power up.
BAS must be:

Set for the same baud rate

Sending requests to the proper address

Reading or writing to the proper point addresses on the controller

Set for the same communication settings (8 Data bits, No Parity, and 1 Stop bit)

Speaking 2-wire 485 to the controller
Software settings defined through the Equipment Touch device. To confirm settings, obtain a Modstat of the
device. On the Equipment Touch, click the link to the Modstat.
NOTES

Refer to Appendix A (page 41) for the Network Points list.

Refer to Appendix C (page 56) for the Protocol Implementation Conformance Statement.
Modbus Exception Codes that might be returned from this controller
Codes
01
02
04
RTU Open v5
Integration Guide
Name Description
Illegal Function The Modbus function code used in the query is not
supported by the controller.
Illegal Data The register address used in the query is not supported
Address by the controller.
Slave Device The Modbus Master has attempted to write to a non-
Failure existent register or a read-only register in the
controller.
13
Communications wiring
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