When automating pneumatic processes, bus modules control the interaction of an electronic fieldbus and pneumatics. Rexroth Mecman, Lexington, Ky., offers a complete line of bus, input, and output modules. Combined with contact bridges or I/O modules, pneumatic valves can be flexibly, reliably, and rapidly integrated into PLC-controlled production processes.

One major feature is an extended diagnostics capability to detect possible errors, such as an actuator short circuit. The malfunction is indicated on the output module and the bus module. The error message is also included in the data protocol transmitted to the control system, thus permitting early detection. Preassembled cable up to 10-m long provides electrical connections. Cables can also incorporate the contact bridge for direct connection of the valve coils.

The bus modules are available for Profibus-DP, Interbus-S, CAN Open, DeviceNet, and 1771 Remote I/O fieldbus protocols. I/O modules and contact bridges can be combined to a maximum 32-bit input data and 32-bit output data per strand. Depending on the protocol, the bus module can handle up to four strands. Inherent intelligence eliminates the need to assign addresses to components, which simplifies and speeds startup and servicing.