System variables - INTERBUS master

Available for AXC F x152

On INTERBUS master devices, three diagnostic registers map the diagnostic display to the control
system:

diagnostic status registers
diagnostic parameter registers
extended diagnostic parameter registers

They inform the control system about the current state of the INTERBUS system. In the application program, operating states, errors, and other information appear as inputs.

Diagnostic status registers

Information on the operating state of the INTERBUS master is stored in the diagnostic status register. A specific INTERBUS master state is assigned to each bit in the diagnostic status register.
The following system variables can be used to read the diagnostic status register information.

Variables in the diagnostic status registers

System variable	Type	Description
IB_DIAG_STATUS_REG_HI	BYTE	Master diagnostic status register, high byte
IB_DIAG_STATUS_REG_LOW	BYTE	Master diagnostic status register, low byte
IB_DIAG_STATUS_REG_SYSFAIL	BOOL	“System failure” error message
IB_DIAG_STATUS_REG_WARN	BOOL	Defined warning time exceeded
IB_DIAG_STATUS_REG_QUAL	BOOL	Defined error density exceeded
IB_DIAG_STATUS_REG_USER	BOOL	User error/parameterization error
IB_DIAG_STATUS_REG_PF	BOOL	Peripheral fault
IB_DIAG_STATUS_REG_BUS	BOOL	Bus error
IB_DIAG_STATUS_REG_CTRL	BOOL	INTERBUS master/hardware fault
IB_DIAG_STATUS_REG_DTC	BOOL	Diagnostic routine is active
IB_DIAG_STATUS_REG_RUN	BOOL	Data transmission is active
IB_DIAG_STATUS_REG_ACT	BOOL	Selected configuration is ready for operation
IB_DIAG_STATUS_REG_RDY	BOOL	The INTERBUS master is ready for operation

Diagnostic parameter registers

The diagnostic parameter register provides additional information on an error indicated in the diagnostic status register and is rewritten whenever a malfunction occurs. If no malfunction has been detected, the diagnostic parameter register contains the value 0.
Exception: If an INTERBUS local bus error cannot be located then the value 128 is indicated in the diagnostic parameter register (i.e., bit 7 is set).

The location in the local bus structure and an error code is stored in the diagnostic parameter register for each error:

Error code, e.g. "address overlap" = code `0A50`hex

For each error code, there's a plain text description and hints to remedy the error, e.g. for the above "address overlap" error:

Error code	Type	Description and remedy
`0A50`hex	BOOL	Error when assigning a process data item. Input or output address assigned more than once. Remedy: Always assign just 1 process data item to each input/output address. Add_Error_Info: PDRL index of the incorrect PDRL entry

Find all error codes and their descriptions in the INTERBUS Diagnostics Guide user manual (Prod.-Id. 2747293, IBS SYS DIAG DSC UM E, and other languages - see Diagnostics - Local bus).

Variables in the diagnostic parameter registers

System variable	Type	Description
IB_DIAG_PARAM_REG_HI	BYTE	Master diagnostic parameter register, high byte
IB_DIAG_PARAM_REG_LOW	BYTE	Master diagnostic parameter register, low byte
IB_DIAG_PARAM_2_REG_HI	BYTE	Extended master diagnostic parameter register, high byte
IB_DIAG_PARAM_2_REG_LOW	BYTE	Extended master diagnostic parameter register, low byte

Extended diagnostic parameter registers

The extended diagnostic parameter register is only updated once the "Confirm_Diagnostics" service (0760hex) has been sent. By default, it is set in the MPM at address 37E6hex and can also be moved to the I/O area using the Set_Value service (Variable_ID 010Chex).