52
5756B
Automatic Diagnostic Functions
Diagnostic Data Evaluation
Diagnostic and Acknowledgment Functions
The INTERBUS system offers automatic diagnostics. It is
automatically activated in the event of an error, and the
diagnostic result is communicated to the user and the PLC
program via the LCD and the diagnostic registers. The user
and the PLC program can now react to the error. The reaction
can take place directly via the standard function register. The
functions stored there, such as "Update diagnostic display"
(PF display) and "Start INTERBUS system" (for a bus error)
are used to acknowledge the error (bits 0 and 2 of the
register). The sample program includes a standard diagnostic
and acknowledgment driver. It evaluates the diagnostic result
(via the diagnostic status register or diagnostic parameter
register) and gives a controlled acknowledgment of the error
(with the standard function registers) automatically or via an
acknowledge input.
Functions used by the standard function start register:
Diagnostic and Acknowledgment Function
FC 24 IB_DIAG
Call Description:
A driver (FC 24) operating in the cyclic program (OB 1)
acknowledges error messages and starts the INTERBUS
system. Acknowledgment is time-controlled or executed by
means of a separate control input (in the example I4.0) or bit
memory.
The diagnostic block described below is part of the
driver example for I/O data transfer on the disk in the
user manual.
Bit 0: Starts the INTERBUS system
Bit 2: Updates the diagnostic display.
