Code 232110: <location>Encoder 2: Se rial communica tions error
Issue Description & Safety Warning
The Siemens SINUMERIK 840D CNC has triggered a critical <location>Encoder 2: Se rial communica tions error 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
Message value: Fault cause: %1 bin Drive object: All objects Reaction: A_INFEED: NONE SERVO: OFF1 (IASC/DCBRAKE, NONE, OFF2, OFF3) VECTOR: OFF1 (IASC/DCBRAKE, NONE, OFF2, OFF3) Acknowledge: PULSE INHIBIT Cause: Serial communication protocol transfer er ror between the encoder and evaluation module. Fault value (r0949, interpret binary): Bit 0: Alarm bit in the position protocol. Bit 1: Incorrect quiescent level on the data line. Bit 2: Encoder does not respond (does not supply a start bit within 50 ms). Bit 3: CRC error: The checksum in the protoc ol from the encoder does not match the data. Bit 4: Encoder acknowledgement error: The encoder incorrectly understood the task (request) or cannot execute it. Bit 5: Internal error in the serial driv er: An illegal mode command was requested. Bit 6: Timeout when cyclically reading. Bit 8: Protocol is too long (e.g. > 64 bits). Bit 9: Receive buffer overflow. Bit 10: Frame error when reading twice. Bit 11: Parity error. Bit 12: Data line signal level error during the monoflop time. Bit 13: Data line incorrect. Remedy: Re fault value, bit 0 = 1: - encoder defective. F31111 may provide additional details. Re fault value, bit 1 = 1: - Incorrect encoder type / repl ace the encoder or encoder cable. Re fault value, bit 2 = 1: - Incorrect encoder type / repl ace the encoder or encoder cable. Re fault value, bit 3 = 1: - EMC / connect the cable shield, r eplace the encoder or encoder cable. Re fault value, bit 4 = 1: - EMC / connect the cable shield, replace the encoder or encoder cable, replace the Sensor Module. SINAMICS-Alarms Diagnostics Manual (DAsl), 03/2009 Re fault value, bit 5 = 1: - EMC / connect the cable shield, replace the encoder or encoder cable, replace the Sensor Module. Re fault value, bit 6 = 1: - Update the firmware for the Sensor Module. Re fault value, bit 8 = 1: - Check the parameterization (p0429.2). Re fault value, bit 9 = 1: - EMC / connect the cable shield, replace the encoder or encoder cable, replace the Sensor Module. Re fault value, bit 10 = 1: - Check the parameterization (p0429.2, p0449). Re fault value, bit 11 = 1: - Check the parameterization (p0436). Re fault value, bit 12 = 1: - Check the parameterization (p0429.6). Re fault value, bit 13 = 1: - Check the data line.
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 232110 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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