A plug for all fieldbuses

Tom Shelley reports on a simple concept that should greatly simplify the setting up of fieldbus based automation systems

A single plug-in device converts most commonly used fieldbus protocols to a neutral format that ABB automation devices can understand. The FieldBusPlug (FBP) only needs an appropriate cable with the right connector to interface to DeviceNet, Modbus, Profibus DP, InterBus , CANopen or AS-I. ABB plans to offer plugs to suit all major fieldbuses on the market. The number of nodes that may be daisy chained from whatever the FBP is attached to depends on the fieldbus. The development allows ABB to offer equipment such as motor controllers and starters in single standard versions. The first units to benefit from FBP technology are: Motor Starter Direct MSD11-FBP, Motor Starter Reverse MSR22-FBP, Motor Fieldbus Interface MF121-FBP and Universal Motor Controllers UMC22-FBP. The latter is designed for motor protection at working currents from 0.24A to 63A. It has six digital inputs at 24VDC and three digital relay outputs. These can be assigned to predefined control functions such as fault input, local control, fault output and check back. The motor start data can be set directly on-site via a removable control panel. Direct, reversing, star-delta and actuator start functions are available. Electronic overload, phase loss and motor blockage are all integrated protection features. The device can also be programmed with a second current setting enabling better fault management for two speed applications. It has trip classes of 5, 10, 20 and 30 as well as phase loss and locked rotor protection. Current ranges up to 800A can be accommodated with an external current transformer. ABB Trevor Kirtley