Pilz ST SB DP S, SW paket PROFIBUS-DP - Manual (Page 14)

Setting Parameters
4-2 PROFIBUS-DP-Slave Operating Manual
Diagnostics
The diagnostics function provides information about the PSS / Slave to the
Master. The standard divides diagnostic information into two areas:
• Internal system diagnostic data
• External diagnostic data
- device-specific diagnostic data
- user-specific diagnostic data
Internal system and device-specific diagnostic data is transferred
automatically. If the PSS(1) DP-S or PSS SB 3006 DP-S receives a
diagnostic message, it will inform the Master that it is present. The Slave
cannot send the diagnostic data until the Master requests it. During
transmission, I/O data traffic (transfer of usable data) is interrupted.
It is also possible to transfer user-specific messages (diagnostic data).
The time of transfer for user-specific messages can be set individually.
The user establishes the event which will trigger the transfer of diagnostic
data.
Application example: a machine's operating status is to be transmitted
constantly (e.g. 10 Bytes). If a certain temperature is exceeded, additional
data will be required (e.g. 40 Bytes). The 10 Bytes for operating status will
be transferred within the usable data; the 40 Bytes of additional data will
be transferred in diagnostics mode. This means that in normal operation,
only small amounts of data are transferred and the communication speed
will be high. In exceptional cases (when the temperature is exceeded),
larger amounts of data must be transferred and the communication speed
will be reduced.
Internal system diagnostics
Standard function block SB 230 prepares data for internal system
diagnostics:
Byte 1 Bit 6: Prm_Fault
Byte 1 Bit 3: Ext_Diag
Byte 1 Bit 1: Station_Not_Ready