Configured for PROFIBUS FMS/DP communication processing in PLC-5 control systems, the Allen-Bradley 1785-PFB (1785-PFB Profibus Module) provides direct communication execution between PLC-5 backplane architecture and PROFIBUS network devices.

Model Identification

Hardware Configuration Details

The 1785-PFB is a PLC-5 coprocessor module designed to add PROFIBUS communication capability to PLC-5 controller systems. The module receives operating power directly from the PLC-5 chassis backplane and exchanges communication data through the PROFIBUS interface.

The module supports PROFIBUS FMS and DP communication modes with selectable communication speeds from 9.6 kbps to 12 Mbps. Electrical isolation between communication circuitry and control system components is provided through the specified isolation voltage rating.

PLC-5 Network Communication Characteristics

The 1785-PFB operates as a dedicated communication interface within PLC-5 platforms. The module handles PROFIBUS data exchange while maintaining PLC-5 backplane communication processes.

Allen-Bradley PLC-5 systems use modular backplane communication architecture. The 1785-PFB expands I/O and communication capability by integrating PROFIBUS connectivity without changing the existing PLC processor structure.

Ordering Information

• 1 x Allen-Bradley 1785-PFB PROFIBUS Coprocessor Module
• Compatible with Allen-Bradley PLC-5 controller chassis systems
• PROFIBUS FMS/DP communication interface included
• 5 VDC backplane power interface included
• No external power supply required

Field Installation Guidelines

Module Mounting

• Install the module in a compatible PLC-5 chassis slot.
• Verify chassis power is removed before module insertion or removal.
• Confirm backplane connectors are clean and properly aligned.

Communication Wiring

• Use PROFIBUS-compatible cabling and connectors for network installation.
• Maintain cable separation from high-voltage power wiring.
• Apply proper grounding and shielding practices for communication cable systems.

System Integration

• Verify PROFIBUS baud rate settings match connected devices.
• Confirm PLC-5 processor configuration supports the installed communication module.
• Check network termination requirements according to PROFIBUS installation standards.

Frequently Asked Questions

• What controller platform is compatible with the 1785-PFB?

  The 1785-PFB is designed for Allen-Bradley PLC-5 control systems and installs through the PLC-5 chassis backplane.

• Which communication protocols are supported?

  The module supports PROFIBUS FMS and PROFIBUS DP communication functions.

• How is the module powered?

  The 1785-PFB receives 5 VDC operating power directly from the PLC-5 backplane.

• What PROFIBUS speed range is supported?

  The communication data rate range is 9.6 kbps to 12 Mbps depending on network configuration.

• Does the module require separate firmware configuration?

  Configuration depends on PLC-5 system setup and PROFIBUS network parameters.

• What is the typical current consumption?

  The module draws approximately 800 mA from the PLC-5 backplane supply.

• Can the module operate outside the specified temperature range?

  Operation should remain within the specified 0 deg C to +60 deg C environmental range.

• Is electrical isolation provided?

  The module includes an isolation voltage specification of 1500 V AC between applicable circuits.