Siemens SINUMERIK Series Function Manual page 41

Overwrite mask
Every NCK analog value set by the part program can be overwritten from the PLC using the
overwrite mask. The previous "NCK value" is lost.
The following sequence has to be carried out to overwrite the NCK value from the PLC:
1. The relevant PLC interface output <n> has to be set to the required analog value.
2. The "setpoint from the PLC" becomes the new "NCK value" when the overwrite mask for
This value remains operative until a new NCK value is programmed (from the PLC or from
the part program).
Setting mask
A PLC setting for each output can determine whether the current "NCK value" (e.g. as
specified by the NC part program) or the "PLC value" specified via the setting mask should
be output at the hardware analog output.
The following sequence has to be carried out to define the "PLC value":
1. The relevant PLC interface output has to be set to the required analog value.
2. The setting mask must be set to "1" for the relevant analog output:
Unlike the overwrite mask, the NCK value is not lost when a value is set in the setting mask.
As soon as the PLC sets "0" in the corresponding setting mask, the NCK value becomes
active again.
Note
The same setpoint is used at the PLC interface for the overwrite and setting masks.
Disable output
Analog NCK outputs can be disabled individually from the PLC user program:
DB10 DBB168 (disable analog NCK outputs)
In this case, the "0" signal is output at the hardware output.
In this case, 0 volt is output at the analog output.
Read setpoint
The current "NCK value" of the analog outputs can be read from the PLC user program:
DB10 DBW210 ... (setpoint of the analog output <n> of the NCK)
Please note that this setpoint ignores disabling and the PLC setting mask. Therefore, the
setpoint can differ from the actual analog value at the hardware output.
Extended Functions
Function Manual, 03/2013, 6FC5397-1BP40-3BA1
DB10 DBW170 ... (setpoint from the PLC for analog output <n> of the NCK)
the relevant analog output is activated (edge change 0 → 1).
DB10 DBB166 (overwrite mask of analog NCK outputs)
DB10 DBW170 ... (setpoint from the PLC for analog output <n> of the NCK)
DB10 DBB167 (Setting screen form of analog NCK outputs)
A4: Digital and analog NCK I/Os for SINUMERIK 840D sl
1.2 Access via PLC
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