Plc Program Blocks; Acknowledgment Process; Types Of Acknowledgment - Siemens SINUMERIK 828D Commissioning Manual

9.4

PLC Program Blocks

9.4.1

Acknowledgment process

Information to tool management
The tool management expects acknowledgment of its orders in order to track and carry the
actual tool positions. At least one acknowledgment is required for each order. This is sufficient
for many applications.
Acknowledgment takes place either via the table defined in DB9902, or in one step with the
total acknowledgment (DB40xx/42xx DBX0.0) after a completely finished tool management
order using a 0/1 edge (set) of the corresponding bits in the user interface.
As long as the acknowledgment signal is present, no changes may be made to the data of this
interface! This signal is reset by the PLC firmware after the acknowledgment has been
transmitted to the tool management. In certain circumstances resetting may take place after
several PLC cycles.
There are further advantages if the tool management is also informed of intermediate positions:
● Information about intermediate positions:
If the intermediate tool positions are known in the tool management, the allocation of the
buffer magazine may be queried. This makes powering up easier after switching off and
on again or after canceling a command (e.g. via reset). If the tool currently being changed
is needed again immediately, it can be loaded back into the spindle from a buffer location
without loading it into the magazine first.
● Information about magazine positions:
If the tool management knows at which magazine location there is a transfer point (changing
point for the spindle, loading point), it can determine the shortest paths in the magazine for
finding an empty location or for selecting a new tool. During orders the tool management
can usually recognize the magazine position from intermediate acknowledgments (e.g. tool
transfer between the real magazine and the buffer) or from the end acknowledgment (e.g.
"magazine positioning" order complete). If the magazine is positioned by the PLC user
program itself (e.g. by means of HMI or machine keys) without a tool management order,
this must be communicated to the tool management via synchronous signals.
9.4.2

Types of acknowledgment

Tool and magazine movements
The tool management distinguishes between synchronous acknowledgment and an
asynchronous job-independent message.
CNC commissioning
Commissioning Manual, 10/2015, 6FC5397-3DP40-5BA3
Tool management
9.4 PLC Program Blocks
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