TP37 datasheet(72/230 Pages) SIEMENS

72 / 230 page

6-22

TP27, TP37 Equipment Manual

Release 01/00

Example:

A CPU 315 can process a maximum of 50 simultaneously pending messages.

Accordingly, an operating unit can handle a maximum of four CPU 315s send-

ing ALARM_S messages without overflow problems occurring.

6.5.5

Updating

Since the CPU stores the message information when a fault occurs, individual

network stations (e.g. an OP) can log on at a later date and obtain an update.

However, the CPU only stores information about pending messages. Once all

events (arrival, departure, acknowledgement) have occurred, the message is

deleted from the CPU.

When obtaining an update, therefore, the operating unit processes any missing

events automatically if a message is not known to the PLC but the arrival and

acknowledgement events are not entered on the operating unit.

The events are not entered in the message buffer in that case, however.

Events processed in this way are identified on the operating unit by displaying

the message status symbols in inverse type thus:

*1234567 A KGQ HH:MM:SS DD.MM.YYYYGRU00

Boiler 13: temperature 190 degrees

Inform shift supervisor Tel. 007

Figure 6-9 Automatically Processed Events

Messages

TP37 Datasheet(PDF) 72 Page - Siemens Semiconductor Group