1 General Overview
05.91
1.3.8 Display of messages
1.3.8
Display of messages
The PLC user program can issue messages at the operator panel. In order to output
messages, message numbers are transferred to the COM area. These message numbers are
independently generated by function blocks (FB 54 - FB 56) that are called by the PLC user
program as required.
The FB called by the user program scans all the memory locations defined as message bytes
and generates message numbers for all the set bits. These message numbers are stored in
message buffers. A distinction is made here between error messages and operational
messages. Many of the bits used to generate messages can trigger a function on the NC, e.g.
spindle disable.
The following message types exist:
•
Channel-specific messages
(bit fields in DB 10 - DB 25)
•
Spindle-specific messages
(bit field in DB 31)
•
Axis-specific messages
(bit field in DB 32) and
•
PLC-specific messages
(bit field in DB 58).
The display programs in the COM area search for the texts or images that belong to the
message numbers they received from the PLC in the user memory submodule (UMS) and
display them.
A set bit generates a message if:
•
The byte containing the bit is defined as a message byte (by MD)
•
The FB package for messages is loaded in the PLC (FB package 0)
•
The relevant FB is called in the PLC user program and if
•
A message text for the bit is stored in the UMS.
The display in the message line depends on DB 58, DW 0. The images (overview alarms PLC)
do not have to be specially programmed; only the texts for the messages have to be specified
in the UMS.
As well as the error and operational messages (parameterized by machine data), messages for
message groups that can be displayed in standard images are also available.
1–32
© Siemens AG 1991 All Rights Reserved 6ZB5 410-0HE02
SINUMERIK 880 (PJ)
