Concept
Communication Port Wiring
The wiring recommendations for the communication ports on the automation servers, RP and MP controllers, IP-IO and RP-IO modules, RP controller expansion modules, and Operator Display devices apply to wires and cables used for RS-485 communications, LonWorks communications, USB connections, Ethernet connections, sensor bus connections, room bus connections, and RP and MP controller Modbus network connections. Always use the recommended cables and wires.
For AS-P servers, the LonWorks wiring is made to the removable terminal blocks. The connections for RS-485 are made to the removable terminal blocks, and the connections for Ethernet and USB are made to the electronics module.
For AS-B servers, the connections for RS-485 are made to the removable terminal blocks and can be done before the AS-B server is installed on the DIN rail. The connections for Ethernet and USB are made directly to the device.
MP-C BACnet/IP controllers have communication ports for Ethernet and USB as well as a configurable RS-485 port, which can be configured for the sensor bus or Modbus network. All connections are made directly to the device. MP-C controllers with “-M” in the product name are BACnet MS/TP controllers and have no communication ports other than the RS-485 screw terminal block used for connection to the MS/TP network. For more information, see MP-C Models .
MP-V BACnet/IP controllers have communication ports for Ethernet and USB as well as a configurable RS-485 port, which can be configured for the sensor bus or Modbus network. The RS-485 port can also be reconfigured to support BACnet MS/TP network communication with the hosting server. For more information, see MP-V BACnet MS/TP Support .For more information, see RS-485 Communications . All connections are made directly to the device.
RP-C BACnet/IP controllers have communication ports for Ethernet and USB, as well as two or three configurable RS-485 ports, which can be configured for the sensor bus, room bus, or Modbus network. One of the RS-485 ports can also be reconfigured to support BACnet MS/TP network communication with the automation server. For more information, see RP-C BACnet MS/TP Support .For more information, see RS-485 Communications . The other RS-485 port(s) can then be configured to support either sensor bus, room bus, or Modbus network. All connections are made directly to the device. RP-C controllers with “-M” in the product name are BACnet MS/TP controllers equipped with one communication port, a configurable RS-485 port that can be configured for the sensor bus or Modbus network, and an RS-485 screw terminal block used for connection to the MS/TP network. For more information, see RP-C Models .
RP-V BACnet/IP controllers have communication ports for Ethernet and USB, as well as two configurable RS-485 ports, which can be configured for the sensor bus, room bus, or Modbus network. One of the RS-485 ports can also be reconfigured to support BACnet MS/TP network communication with the automation server. For more information, see RP-V BACnet MS/TP Support .For more information, see RS-485 Communications . The other RS-485 port can then be configured to support either sensor bus, room bus, or Modbus network. All connections are made directly to the device. RP-V controllers with “-M” in the product name are BACnet MS/TP controllers equipped with one communication port, a configurable RS-485 port that can be configured for the sensor bus or Modbus network, and an RS-485 screw terminal block used for connection to the MS/TP network. For more information, see RP-V Models .
IP-IO modules are BACnet/IP devices and have communication ports for Ethernet and USB. All connections are made directly to the device.
RP-IO modules are BACnet MS/TP devices and have no communication ports other than the RS-485 screw terminal block used for connection to the MS/TP network.
RP controller expansion modules have communication ports for room bus. All connections are made directly to the device.
Operator Display devices have communication ports for Ethernet and USB. All connections are made directly to the device.
RS-485 Communications
The information in this section provides recommendations for the RS-485 interface port configuration between the automation server and RS-485 network devices. This information is intended to supplement existing guides for the automation server and for the various RS-485 network devices.
For more information, see RS-485 Communications .
LonWorks Communications
Twisted pair cables should be used between the FTT-10 interface on the AS-P server terminal base and the TP/FT-10 LonWorks network. The cables should conform to the standard EN 50173-1.
USB Connections
Standard USB cables should be used for connection to the USB host and device ports on the automation server, BACnet/IP device, and Operator Display. The recommended maximum cable length is 3 m (10 ft).
Ethernet Connections
Standard Ethernet cables with RJ45 connectors should be used for connection to the Ethernet 10/100 port(s) on the automation server, BACnet/IP device, and Operator Display.
Standard UTP Ethernet cables are recommended for the network connections.
Shielded network cables are not recommended but can be used on cable sections extending through noisy electrical environments. Shielded network cables cause ground loops. The grounded RJ45 network connector passes the local ground from a device to the shield of the cable, which in turn passes to the ground of the subsequent device. The devices can be automation servers, BACnet/IP devices, or third-party IP controllers, interface devices, network switches or routers, or telecom switch equipment.
Shield-induced ground loops can cause the following problems:
Degraded performance on communications network
Interruption of communication-dependent process control execution
Unstable operation and/or restart of the two devices
Damage to one or both devices
The objective is to minimize the potential problems created with ground loops in the facility. The effects and risks with ground loops are reduced when the devices are served from the same AC power distribution panel and the devices are in the same general area of the facilities' metal and grounding structure.
Sensor Bus Connections
Cat 5 (or higher) cables with eight conductors (four twisted pairs) and RJ45 connectors should be used for connection to the MP or RP controller RS-485 port that is used for the sensor bus and the RJ45 port(s) on the SpaceLogic Sensor devices.
On an MP-C BACnet/IP controller, the cable is connected to the RS-485 Com A port, which is configured for the sensor bus by default. For more information, see Communication Ports on MP-C-15A, -18A, -18B, -24A, and -36A .
The labeling of the RS-485 port differs between different versions of the MP-C controller models. In previous versions, the port is labeled “Sensor Bus”.
On an MP-V BACnet/IP controller, the cable is connected to the RS-485 Com A port, which is configured for the sensor bus by default. For more information, see MP-V Communication Ports .
The labeling of the RS-485 port differs between different hardware versions of the MP-V controller models. In previous versions, the port is labeled “Sensor Bus”. For more information, see Differences Between MP-V Hardware Versions .
On an RP controller, the cable is connected to the RS-485 port that is configured for the sensor bus. By default, the RS-485 Com A port is configured for the sensor bus. For more information, see RP-C Communication Ports .For more information, see RP-V Communication Ports .
The labeling of the RS-485 ports differs between different hardware versions of the RP-C controllers. For more information, see Differences Between RP-C Hardware Versions .
The wire size (cross-sectional area) should be 22 to 26 AWG (0.34 to 0.14 mm²). The sensor bus cables should be rated for the target environment. For example, when the MP or RP controller is installed in space handling conditioned air or return air, the cables should be plenum-rated. The cables should be located away from external electrical noise sources such as high voltage cables or signal cables, which can cause data communication problems. The maximum total length of the sensor bus is 61 m (200 ft).
UTP (unshielded twisted pair) cables are recommended for the sensor bus.
Shielded cables are not useful to use for the sensor bus, because the RJ45 receptacles on the controllers and SpaceLogic Sensor devices do not support grounding of the shield.
Room Bus Connections
The RP controller room bus allows RP controller expansion modules to be connected to the controller for people counting, motion detection, luminosity and sound pressure level measurements, Bluetooth Low Energy based applications, and control of electric lights and window blinds.
Cat 5 (or higher) cables with eight conductors (four twisted pairs) and RJ45 connectors should be used for connection to the RP controller RS-485 port that is configured for the room bus and the RJ45 port(s) on the RP controller expansion modules. By default, the RP controller RS-485 Com B port is configured for the room bus. For more information, see RP-C Communication Ports .For more information, see RP-V Communication Ports .
The wire size (cross-sectional area) should be 22 to 26 AWG (0.34 to 0.14 mm²). The room bus cables should be rated for the target environment. For example, when the RP controller is installed in space handling conditioned air or return air, the cables should be plenum-rated. The cables should be located away from external electrical noise sources such as high voltage cables or signal cables, which can cause data communication problems. The maximum total length of the room bus is 72 m (236 ft).
UTP (unshielded twisted pair) cables are recommended for the room bus.
Shielded cables are not useful to use for the room bus, because the RJ45 receptacles on the RP controllers and RP controller expansion modules do not support grounding of the shield.
Modbus Network Connections
The RP and MP controller Modbus RTU (RS-485) subnetworks allow standard Modbus devices to be connected to the controller. The RP BACnet/IP controller also allows the connection of a KNX Modbus gateway (RP-C-EXT-KNX).
It is recommended to use the Non-isolated RS-485 Adapter (SXWNISORS48510001) to provide screw termination of the Modbus device wiring and help avoid miswiring. The adapter converts an RS-485 RJ45 interface to screw terminals. For more information, see Non-isolated RS-485 Adapter .
For the KNX Modbus gateway, the RS-485 Power Adapter (SXWNISORS485P10001) can preferably be used to convert the RP controller RS-485 interface from RJ45 port to screw terminals because this adapter supports 24 VDC power supply from the controller to the KNX Modbus gateway. For more information, see RS-485 Power Adapter .
The maximum total length of the Modbus (RS-485) network is 72 m (236 ft).
Cable selection is important to achieve good performance and reliability of the Modbus (RS-485) network. The cable must provide twisted pairs and be specified for RS-485 data communications. It is recommended to use a shielded, low-capacitance twisted pair cable with an impedance of 120 ohm and a wire size (cross-sectional area) of 22 to 24 AWG (0.33 to 0.20 mm²). For more information, see Cable Selection .
Termination resistors can be omitted due to the limited length of the Modbus (RS-485) network and due to the use of twisted pair cables.
The Modbus (RS-485) network cable should be routed in a continuous daisy-chain bus configuration without cable stubs. For more information, see Cable Routing .
The Modbus cables should be rated for the target environment. For example, when the controller is installed in space handling conditioned air or return air, the cables should be plenum-rated. The cables should be located away from external electrical noise sources such as high voltage cables or signal cables, which can cause data communication problems.
On the RP BACnet/IP controller, you need to configure which of the two RS-485 ports to use for the Modbus network. You can configure to use either the RS-485 Com A or Com B port, which by default are configured for the sensor bus and room bus respectively. The RP-C-16C-F-230V model differs in that it has a third RS-485 port (RS-485 Com C), which by default is configured for the Modbus network. On the RP BACnet MS/TP controller (with “-M” in the product name), you need to reconfigure the single RS-485 port to use for the Modbus network. The port is by default configured for the sensor bus. For more information, see RP-C Communication Ports .For more information, see RP-V Communication Ports .
On the MP BACnet/IP controller, you need to reconfigure the single RS-485 port to use for the Modbus network. The port is by default configured for the sensor bus. For more information, see Communication Ports on MP-C-15A, -18A, -18B, -24A, and -36A .For more information, see MP-V Communication Ports .
Shielded, low-capacitance twisted pair cables specified for RS-485 data communications are recommended for the Modbus network. For more information, see Cable Selection .
Wiring
AS-P Servers
AS-B Servers
MP-C Controllers
MP-C Models
MP-V Controllers
MP-V Models
RP-C Controllers
RP-C Models
RP-V Controllers
RP-V Models
IP-IO Modules
RP Controller Expansion Modules
Non-isolated RS-485 Adapter
RS-485 Power Adapter
RS-485 Communications
Cable Routing
Cable Selection
Communication Ports on MP-C-15A, -18A, -18B, -24A, and -36A
MP-V Communication Ports
Differences Between MP-V Hardware Versions
RP-C Communication Ports
Differences Between RP-C Hardware Versions
RP-V Communication Ports
Operator Display Communication Ports
RJ45 Pinout for the RS-485 Port of the MP-V Controller
RJ45 Pinout for the RS-485 Port of the MP-C Controller
RJ45 Pinout for the RS-485 Port(s) of the RP-C Controllers
RJ45 Pinout for the RS-485 Ports of RP-C-16C-F-230V
RJ45 Pinout for the RS-485 Port(s) of the RP-V Controllers
MP-V BACnet MS/TP Support
RP-C BACnet MS/TP Support
RP-V BACnet MS/TP Support