Interface To Nc Channels - Siemens SINUMERIK 880 SW 6 Planning Manual

6 NC Channel/PLC Interface (DB 10 ... DB 25)

6.3 Interface to NC channels

6.3 Interface to NC channels
The channel-specific NC/PLC interface is stored in data blocks DB 10 (channel 1) - DB 25
(channel 16).
The PLC machine data bits:
PLC I = MD 6000, 6001
PLC II = MD 6100, 6101
can be set to determine which PLC processes which NC channel.
Note:
On GA2, software version 1 and higher, you can only select up to eight channels out of 16
because no more than two NC CPUs can be used.
When working with two PLCs, the PLC machine data bits:
PLC I = MD 6003, 6004
PLC II = MD 6103, 6104
can be set in addition to determine whether the other PLC can also evaluate to the NC/PLC
interface signals.
By way of a further PLC machine data:
PLC I = MD 6006, 6007
PLC II = MD 6106, 6107
the PLC that can only send the signals on the NC/PLC interface can be set to output the
FEED DISABLE and READ-IN DISABLE signals to the NC.
Several bits are available in each case for the signals GENERAL FEED DISABLE, READ-IN
DISABLE and NC START DISABLE. If, for example, a different bit is set for each machine
function that has to activate feed disable, it is easy to determine which function initiated feed
disable in the event of a fault. Each set bit can be allocated a message text so that the
operator can be informed of the diagnosis. This function is described in detail in the "Display
of messages" Section.
Since signal processing in data blocks is a tedious process, two function blocks (FB 70 and
FB 71) are available to permit the exchange of signals between data words and flag words.
The following figures show the structural principle of channel allocation and the assignment of
data bytes to flag bytes.
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6 4 ©
Siemens AG 1991 All Rights Reserved
05.91
6ZB5 410-0HE02
SINUMERIK 880 (PJ)