Siemens SINUMERIK 840Di Function Manual page 617

Start command, channel status
There are two possible START commands for initiating processing of a part program or part
program block:
• The channel-specific interface DB21, ... DBX7.1 (NC Start), which is usually controlled
• With the NC instruction START, program execution in the first channel can be started
The START command can only be executed in AUTOMATIC and MDA modes. The relevant
channel must have status DB21, ... DBX35.7 (Channel status reset) or DB21, ... DBX35.6
(channel status interrupted).
Signals, Alarms
Required signal states
The part program can now be enabled for execution in the channel with the START
command on the condition that certain signal states exist on the machine.
Relevant enable signal settings:
• DB11, ... DBX4.4 (mode group ready) must be present
• DB11, ... DBX0.7 (mode group reset) must not be present
• DB21, ... DBX1.7 (activate program test) must not be present
• DB21, ... DBX7.0 (NC start disable) must not be present
• DB21, ... DBX7.2 (NC stop at the block limit) must not be present
• DB21, ... DBX7.3 (NC Stop) must not be present
• DB21, ... DBX7.4 (NC Stop axes plus spindle) must not be present
• DB21, ... DBX7. 7 (reset) must not be present
• DB10, DBX56.1 "EMERGENCY STOP" must not be present
• No axis or NCK alarm must be active
For descriptions of the individual signals see Chapter 5.
Execution of command
The part program or part program block is automatically processed and interface signals:
DB21, ... DBX35.5 ("Channel status active")
and
DB21, ... DBX35.0 ("Program status running") are set.
The program is processed until the end of the program has been reached or the channel is
interrupted or aborted by a STOP or RESET command.
Mode Group, Channel, Program Operation, Reset Response (K1)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
from the machine control panel key NC Start, starts program execution in the same
channel.
from the second channel, for example (for further information, see Section on Channel
synchronization).
Detailed Description
2.7 Program operation mode
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