Features:
- The coupler translates PROFIBUS DP communication to a PROFIBUS PA or Foundation Fieldbus H1 segment.
- Integrated fieldbus power supplies up to 1 A for as many as 31 connected PA devices.
- Redundancy support and separate activity, fault and supply indicators expose the state of each bus side.
The fieldbus side runs at 31.25 kbit/s, giving every attached instrument a shared communication segment and power path through the coupler.
Five milliseconds of supply-failure buffering keeps the internal electronics energized through a brief input interruption.
Potential separation is maintained among the backplane, PROFIBUS DP, PROFIBUS PA and 24 V supply circuits, with isolation tested at 600 V DC.
The Siemens 6ES7157-0AC85-0XA0 FDC 157 Field Device Coupler may still be available for purchase and support from Apter Power beyond End-Of-Life (EOL) by the manufacturer (OEM).
Siemens 6ES7157-0AC85-0XA0 FDC 157 Field Device Coupler Manuals,Datasheets,Link
Important Notice: Other accessories, manuals, cables, calibration data, software, etc. are not included with this equipment unless listed in the above stock item description. All prices are shown in USD.
Data path between bus levels
- DP input: The 9-pin Sub-D interface receives PROFIBUS DP telegrams at up to 45.45 kbit/s.
- Fieldbus output: The lower-level PA or FF H1 segment communicates at 31.25 kbit/s.
- Shared segment: Up to 31 field devices use the same downstream communication path.
- Protocol choice: The installed bus-link architecture determines whether the field side operates as PROFIBUS PA or Foundation Fieldbus H1.
Supply path to field devices
- Input source: A nominal 24 V DC feed powers the coupler through its protected supply input.
- Field output: The integrated bus supply can deliver a combined maximum of 1 A to the PA segment.
- Device loading: The total current demand of all connected instruments must stay within the segment-current limit.
- Redundant feed: The lower-level bus can use one FDC 157 or one redundant coupler pair.
Front-panel diagnostic separation
- DP activity: A yellow indicator reports communication activity on the PROFIBUS DP side.
- PA activity: A separate yellow indicator reports traffic on the downstream fieldbus segment.
- Fault location: Red BF and SF indicators distinguish a bus fault from a group error condition.
- Supply state: The green ON indicator confirms that the 24 V input is present.
Electrical and environmental boundaries
- Circuit separation: Backplane, DP, PA and supply circuits are electrically separated from one another.
- Test level: The specified isolation test between circuit domains is 600 V DC.
- Input protection: Reverse-polarity and overvoltage protection guard the 24 V supply connection.
- Cabinet requirement: IP20 protection requires installation inside suitable protected equipment across the -25 to 60 °C operating range.