ABB Wireless Controller ARC600 Communication

Communication

Wireless Controller ARC600 provides a complete solution for

monitoring and controlling field devices. A secure

communication channel can be formed for remote serial

(RS-232/RS-485) or Ethernet field devices over a GPRS, 3G

or LTE connection. ARC600 makes it possible to have cost

effective communication networks over long distances at high data rates.

Several interfaces are available for field device connectivity:

digital inputs and outputs, analog inputs, serial and Ethernet

ports. Industrial protocols IEC-104. IEC-101 and Modbus

TCP are supported for the SCADA connectivity. The inputs

and outputs of ARC600 can be accessed and controlled with

the IEC-104 and IEC-101 protocols.

With the Wireless Controller ARC600 protocol conversion

feature, conventional IEC-101. Modbus RTU and Modbus

TCP devices can be connected in a reliable way to modern

TCP/IP based IEC-104 control systems.

Modbus to IEC-104 conversion

ARC600 provides support for generic Modbus RTU and

Modbus TCP devices such as ABB's RIO600. In addition,

support is also provided for the preselected Modbus

parameters for Fault Passage Indicators (FPI). Currently,

Horstmann Compass B and Kries IKI-50 are supported.

ARC600 polls the fault indicator devices, connected to the

serial port, using Modbus protocol and converts the values to

IEC 60870-5-104. Up to four fault indicators can be

connected to one device. IEC 60870-5-104 is used to

communicate towards a SCADA via the Arctic M2M Gateway

over the available customer chosen cellular data network.

IEC-101 to IEC-104 conversion

With ARC600. conventional IEC 60870-101 serial devices can

be attached to a modern TCP/IP based IEC 60870-5-104

control system. This is enabled by the protocol conversion

from IEC 60870-5-101 to IEC 60870-104. In this case,

ARC600 (IEC-101 master) uses local synchronous data

polling where it continuously sends requests and the IEC-101

device (IEC-101 slave) responds. In the direction of the

control room, the communication protocol is IEC-104 and

ARC600 can send events asynchronously as they arise while

SCADA performs only slow-period background scans.

Another advantage of the local protocol conversion is an

advanced data acknowledgement mechanism. IEC-104

allows multiple packets, and multiple events in a single

packet, to be acknowledged collectively and the packets can

be buffered up to the time of acknowledgement from SCADA.

Modbus RTU to Modbus conversion

Modbus field devices use usually serial mode (RTU or ASCII)

protocol while the SCADA communication uses TCP/IP based

Modbus TCP protocol. The Modbus user community has

defined the functionality for required protocol integration, that

is, how the Modbus RTU devices can talk to the Modbus TCP

SCADA system. This functionality is a protocol conversion

and it is implemented in ARC600. Many industrial devices like

PLCs and RTUs support RS-485 Modbus RTU mode. In

RS-485 mode, ARC600 can integrate unlimited number of

serial slaves to TCP/IP network (SCADA).

ARC600 has two application serial ports. Serial port 1 is

configurable to either console or data mode and it supports

only RS-232. while serial port 2 is configurable to multiple

serial modes (RS-232/RS-422/RS-485). Serial port

connectors are 9-pin D-sub (male) connectors.