Omron SYSMAC CJ2 CPU Unit

This word (A10101) will contain the value '0001 hex' when the CPU Unit fails to receive synchronous input data from a Synchronous Unit within the specified time window. This indicates a loss of synchronization or communication with the connected unit. A value of '0000 hex' indicates normal operation.

This flag indicates a general Task Error. This occurs when an unspecified error is detected during the execution of a program task within the CPU. This can encompass a range of runtime issues.

This flag indicates an Indirect DM/EM Addressing Error. This error occurs when an indirect address calculation for DM (Data Memory) or EM (Expansion Memory) results in an invalid, non-existent, or out-of-range memory address. This prevents proper data access.

This flag indicates an Illegal Area Access Error. This fault occurs when the program attempts to read from or write to a memory area that it does not have permission to access, is outside of defined boundaries, or is reserved by the system. This is a critical memory protection violation.

This flag indicates that the mandatory END(001) instruction is missing from the PLC program. Every executable PLC program segment must properly terminate with an END(001) instruction to define its logical end. Absence of this instruction prevents proper program execution.

This flag indicates a Distribution Overflow Error. This error typically refers to an arithmetic overflow that occurs during calculations involving distribution or scaling operations. The result exceeds the maximum representable value for the data type, leading to incorrect values.

This flag indicates an Illegal Instruction Error. This occurs when the CPU encounters an instruction that is either not recognized, malformed, or invalid for the current operating mode or CPU hardware type. This is a critical program execution fault.

This flag indicates a User Memory (UM) Overflow Error. This error typically occurs when the program attempts to utilize more user memory than is currently available or allocated within the CPU unit. This can lead to system instability.

This flag turns ON if an overflow or underflow condition occurs when an interrupt input is received for Pulse Output 3. It also indicates an error if overflow/underflow occurs while moving the specified number of pulses after starting output with the IFEED(892) instruction. An ON state of this flag indicates an error condition.

This flag indicates that memory corruption has been detected within the PLC. When this flag goes ON, the 'Number of Power Interruptions' (A514) will be cleared. This suggests a significant issue with the integrity of the PLC's internal memory or stored data.

This fault occurs when a Special I/O Unit's unit number is duplicated, or when a Special I/O Unit's allocated memory words conflict with a Basic I/O Unit on an Expansion Rack due to an incorrect starting word setting. When this error occurs, the CPU Unit operation will stop, and the ERR/ALM indicator on the front of the CPU Unit will light. The Duplication Error Flag (A401.13) and the corresponding specific unit flag (A411.00 to A416.15) will be set to ON.

This fault indicates a setting error for a Special I/O Unit. When a Special I/O Unit Setting Error occurs, A402.02 and the bit in A428 to A433 corresponding to the Unit's unit number (0-95) are turned ON. The CPU Unit will continue operating, and the ERR/ALM indicator on the front of the CPU Unit will flash. These flags are refreshed when power is turned ON or I/O is recognized.

This fault indicates a setting error for a CPU Bus Unit. When an CPU Bus Unit Setting Error occurs, A402.03 and the bit in A427 corresponding to the Unit's unit number (0-F) are turned ON. The CPU Unit will continue operating, and the ERR/ALM indicator on the front of the CPU Unit will flash. These flags are refreshed when power is turned ON or I/O is recognized.

This fault indicates an error during data exchange between the CPU Unit and a Special I/O Unit. When this error occurs, the Special I/O Unit Error Flag (A402.06) is turned ON. The corresponding bit for the unit number (0-95) in A418 to A423 will also be set. The CPU Unit will continue operating, and the ERR/ALM indicator on the front of the CPU Unit will flash.

This fault indicates an error during data exchange between the CPU Unit and a CPU Bus Unit. When this error occurs, the CPU Bus Unit Error Flag (A402.07) is turned ON, and the bit in A417 corresponding to the unit number of the Unit where the error occurred is turned ON. The CPU Unit will continue operating, and the ERR/ALM indicator on the front of the CPU Unit will flash.

This fault occurs when duplicated refreshing is performed for a Special I/O Unit. When the Duplicate Refresh Error Flag (A402.13) is ON, bit A426.15 indicates the cause of the error, and bits A426.00 to A426.11 contain the unit number (0-95) of the affected Special I/O Unit. The CPU Unit will continue operating, and the ERR/ALM indicator on the front of the CPU Unit will flash.

This error occurs when the total number of I/O points configured in the I/O Table (excluding Slave Racks) exceeds the maximum allowed for the CPU Unit, or when the number of interrupt input points exceeds 32, or when the number of Expansion Racks exceeds the maximum. The CPU Unit operation will stop, and the ERR/ALM indicator on the front of the CPU Unit will light. Details on the specific cause are provided by A407.13 to A407.15.

These bits provide a 3-digit binary value indicating the specific cause of a 'Too Many I/O Points' error (A407.00 to A407.12). The CPU Unit operation will stop and the ERR/ALM indicator will light.

When an error occurs in a Basic I/O Unit, this word stores the slot number (00 to 09 hexadecimal) where the error was detected. The CPU Unit continues operating, but the ERR/ALM indicator on the front of the CPU Unit will flash. The presence of this error is also indicated by A402.12 being ON.

When an error occurs in a Basic I/O Unit, this word stores the Rack number (00 to 03 hexadecimal) where the error was detected. The CPU Unit continues operating, but the ERR/ALM indicator on the front of the CPU Unit will flash. The presence of this error is also indicated by A402.12 being ON.

This flag turns ON when an Expansion Rack's starting word address, set in CX-Programmer, either overlaps with another Rack's allocation or exceeds the maximum address CIO 0901. Bits 00 to 03 correspond to Racks 0 to 3. The CPU Unit operation will stop and the ERR/ALM indicator on the front of the CPU Unit will light.

This flag turns ON when a CPU Bus Unit's unit number has been duplicated. Bits 00 to 15 correspond to unit numbers 0 to F. The Duplication Error Flag (A401.13) will also turn ON. The CPU Unit operation will stop, and the ERR/ALM indicator on the front of the CPU Unit will light.

This flag indicates a Duplicate Refresh Error within the CPU. It occurs when a Special I/O Unit IORF(097) or FIORF(225) instruction for interrupt task I/O refresh is executed twice within a minimum interval of 10 ms. This leads to a conflict in I/O refresh operations.

This flag turns ON when a parity error occurs during RS-232C communication. This indicates a data transmission integrity issue at the RS-232C port. This error flag is valid in Serial Gateway mode.

This flag turns ON when a framing error occurs during RS-232C communication. This indicates that the received data frame does not have a valid start and stop bit sequence, often due to mismatched baud rates or data formats. This error flag is valid in Serial Gateway mode and for Polled Units in Serial PLC Link Mode.

This flag turns ON when an overrun error occurs during RS-232C communication. This means the CPU was unable to process received data before the next character arrived, leading to data loss in the receive buffer. This error flag is valid in Serial Gateway mode and for Polled Units in Serial PLC Link Mode.

This flag turns ON when a timeout error occurs during RS-232C communication. This indicates that a response from the connected device was not received within the expected timeframe after a transmission. This error is valid in Serial Gateway mode, NT Link mode, and for both Polling and Polled Units in Serial PLC Link Mode.