ABB 200-CI485G Communication Interface

Technical Specifications and Interface Design

This communication interface provides RS-485 connectivity for ABB AC500 and AC31 PLC systems. The ABB 200-CI485G enables serial communication with drives, HMIs, and third-party devices. You can install this module onto any compatible CPU or bus coupler. Its compact design requires no additional rack or mounting hardware. The interface weighs approximately 0.08 kilograms. Its dimensions measure 8 cm in height, 5 cm in width, and 3.5 cm in depth.

Parameter	Specification
Brand	ABB
Model	200-CI485G
Category	Communication Interface / RS-485 Serial Adapter
Weight	0.08 kg
Height	8 cm
Width	5 cm
Depth	3.5 cm
Interface Type	RS-485 (2-wire or 4-wire, selectable)
Communication Speed	9.6 Kbps to 115.2 Kbps
Maximum Cable Length	1200 meters at 9.6 Kbps
Number of Nodes	Up to 32 devices per segment
Protocols Supported	Modbus RTU (master/slave), ABB CP400
Termination Resistor	Built-in, selectable via DIP switch
Bias Resistors	Built-in, selectable via DIP switch
Electrical Isolation	500V DC (optional external)
Connection Type	9-pin D-sub (female) or screw terminal
Power Supply	5V DC (from CPU via bus)
Power Consumption	0.5 Watts maximum
Energy Storage	None (no battery)
Component Count	Single PCB with RS-485 driver and protection circuits

RS-485 Communication and Networking

The interface converts the CPU’s internal bus to RS-485 physical layer signals. This standard enables long-distance communication in noisy industrial environments. The ABB 200-CI485G supports both 2-wire half-duplex and 4-wire full-duplex configurations. You can set the communication speed using the programming software. The interface automatically detects the baud rate when configured as a slave. A green LED indicates power and communication activity on the network. The module includes built-in termination and bias resistors for network stability.

Protocol Support and Data Exchange

The interface implements the Modbus RTU protocol for universal compatibility. You can configure the module as a Modbus master or slave device. The ABB 200-CI485G also supports the ABB CP400 protocol for operator panels. The CPU exchanges data with the interface through internal system memory. You do not need special function blocks for basic communication tasks. A yellow LED flashes when the interface transmits or receives data. The module handles CRC checking and exception responses automatically.

Installation and Network Guidelines

You must plug this interface into the dedicated communication slot on the CPU. The module does not require any external power supply for operation. The ABB 200-CI485G draws all power from the CPU through the bus connector. You must use shielded twisted-pair cable for all RS-485 connections. This cable must terminate at both ends with the built-in 120-ohm resistors. You should enable bias resistors on only one device per network segment. The interface requires no external battery for normal communication operation. The operating temperature ranges from -20°C to +60°C.