Symbio™ 700 - Communication Wiring for BACnet® & Modbus™ (J17) & Ethernet Connections

Serial communication wiring lands on the removable J17 Connector on the Symbio 700 board.

Terminal Details & Daisy Chaining

• Polarity Sensitive: Observe correct polarity when connecting communication leads. Connect positive (+) to + and negative (-) to -.
• Internal Common Shunt: The two (+) terminals and the two (-) terminals on the J17 block are wired internally in parallel.
• Daisy Chain Wiring: Use the first set of + / - terminals for the incoming comm trunk and the second set of + / - terminals for the outgoing run to the next device. This eliminates the need to splice two wires under a single screw clamp.

CAUTION: Polarity & Shield Grounding

• Do not cross polarities: Inverted + and - leads on any device on an RS-485 trunk will disrupt communication across the entire segment.

• Shield Grounding: Connect the drain/shield wire continuously through the network segment and ground at one end only (typically at the system controller/building automation panel), never at both ends.

For direct IP integration or high-speed building automation networks, use the integrated RJ-45 Ethernet port at the top-left corner of the Symbio 700 board (next to the USB-B service port).

For network installations using IP-based communications:

• Connector: Standard 8-pin RJ-45 jack located on the Symbio 700 controller.

• Cable Standard: Category 5e (Cat 5e) or Category 6 (Cat 6) shielded or unshielded twisted-pair (STP/UTP), terminated to EIA/TIA 568B standard.

• Network Topology: Connect directly to the building automation system (BAS) Ethernet switch or field service router.

Before commissioning the controller via Tracer® TU or the Symbio Service App, verify the following physical checks:

• License: Advanced license needed. The Symbio UC module display will show Symbio 700 Ready Advanced.

• Physical Seating: J17 terminal block is firmly seated in its connector receptacle.

• Wire Gauge: Use 18-22 AWG shielded twisted-pair cable for serial connections (RS-485).

• Polarity Match: All devices sharing the J17 trunk match (+) to (+) and (-) to (-).

• End-of-Line (EOL) Termination: Proper 120-ohm termination resistance applied at the physical end of the MS/TP trunk (if Symbio 700 is the final node).

• Ethernet Link LED: When using BACnet/IP, verify that the green Ethernet Link/Activity LED is solid or flashing.

MSTP Device ID and Baud Rate Using the Phone App: Setting up Symbio 700 MSTP Device ID and Baud Rate Using the Phone App – Trane Commercial HVAC Help Center

BACnet/IP Using the Phone App: Setting Up Symbio 700 BACnet/IP Using the Phone App – Trane Commercial HVAC Help Center