Code 27302: F_DP: Double assignment MD %1[%2] - MD %3[%4]
Issue Description & Safety Warning
The Siemens SINUMERIK 840D CNC has triggered a critical F_DP: Double assignment MD %1[%2] - MD %3[%4] alarm. Immediate attention from a qualified operator or maintenance technician is required to prevent secondary damage to the equipment or spoiled parts during the manufacturing cycle. Always ensure standard safety and LOTO procedures are followed before accessing electrical cabinets.
Official Troubleshooting Steps
Parameters: %1 = MD name 1 %2 = MD array index for MD name 1 %3 = MD name 2 %4 = MD array index for MD name 2 Definitions: An illegal double assignment has been parameterized in the stated MD: - %1 and %3 = $MN_SAFE_RDP_ASSIGN: SPL inputs ($A_INSE) are multiply occupied by F_DP communication. - %1 and %3 = $MN_SAFE_SDP_FILTER: F user data of an F_SENDDP are multiply occupied by sub-slots - %1 and %3 = $MN_SAFE_SDP_LADDR, $MN_SAFE_RDP_LADDR: Logical basic addresses are mu ltiply occupied by SPL connections - %1 and %3 = $MN_SAFE_SDP_FILTER: System variable assignments ar e multiply occupied by SPL connections - %1 and %3 = $MN_SAFE_SDP_ID, $MN_SAFE_RDP_ID: Parameter DP_DP_ID is multiply occupied by different SPL connections %2 and %4: MD index of SPL connection Reaction: Mode group not ready. Channel not ready. NC Start disable in this channel. Interface signals are set. Alarm display. NC Stop on alarm. Remedy: Correct the MD. Program Continuation: Switch control OFF - ON.
Source: SINUMERIK 840D sl / 840Di sl / SINAMICS S120 Diagnostics Manual (DAsl, 03/2009)
Last reviewed: 2026-07-01 · Verified against the manufacturer’s official documentation.
About Siemens SINUMERIK 840D CNC Alarms
Siemens controllers include extensive self-diagnostics that flag or halt the machine when a fault is detected. Error code 27302 on the SINUMERIK 840D CNC identifies one specific fault condition — its documented cause and the official corrective steps are listed above, sourced from Siemens's service documentation. Always confirm against the manual for your exact machine configuration and follow LOTO procedures before servicing.
Complete Alarm List: 4014 Siemens SINUMERIK 840D CNC codes.
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