Routines; Standard Routines - Siemens SINUMERIK 840 Planning Manual

4 COM

4.2 Routines

4.2 Routines
The input buffer processing task cyclically calls on the interface module and PLC input buffers.
If the cyclic monitoring fails between interface module and COM, the input processing task
blocks itself.
If the task finds a valid entry, it calls the data distribution module. On the basis of the address
information belonging to the message frame, this module performs the distribution to the
corresponding unit.
These processing units are the PLC, the interface modules and the standard routines.
4.2.1

Standard routines

Connection monitoring
The function "connection monitoring" is executed on the COM CPU (communication CPU) via
a standard routine. With this function the connection to the CNC control can be monitored by a
remote node. Connection monitoring consists of a simple sequence of message frames.
Remote node
1. Action message frame (connection monitoring)
2. Response message frame (connection monitoring)
Connection monitoring is always initiated by the remote partner.
The response message frame is always output to this remote partner.
The distributor on the COM area activates the standard routine and enters the address of the
input buffer into the transfer buffer.
The standard routine retrieves the function number from the input buffer in the dual port RAM
and evaluates it. If this has the value 10, the standard routine generates a response message
frame. If not, the input buffer is acknowledged with error number.
To generate the response message frame the standard routine also transmits the address data
"sender location" and "logical partner sender" from the input buffer into the processing buffer.
The "sender location" is required in order to send the response message frame to the
interface module from which the initiation message frame came.
"Sender location"
CP1 - 1st interface module (CP: Communication processor)
CP2 - 2nd interface module
4–2
SINUMERIK 8X0
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SINUMERIK 840/880 (PJ)