Nck Analog Inputs/Outputs; Nck Analog Inputs - Siemens SINUMERIK 840D sl Function Manual

Digital and analog NCK I/Os (A4)
1.2 NCK I/O via PLC
1.2.4

NCK analog inputs/outputs

1.2.4.1

NCK analog inputs

Amount
General machine data is used to define available analog NCK inputs:
MD10300 $MN_FASTIO_ANA_NUM_INPUTS(Number of analog NCK inputs)
Function
The value of the analog NCK input [n] can be accessed directly in the part program using
system variable $A_INA[n].
The analog value at the hardware input can also be influenced by the PLC user program
(see fig.).
Disable input
The PLC user program is capable of disabling the NCK inputs individually using interface
signal
DB10 DBB146 (disable analog NCK inputs).
In this case, they are set to "0" in a defined manner inside the control.
Set input from PLC
The PLC can also specify a value for each analog NCK input using interface signal
DB10 DBB147 (setting mask for analog NCK inputs) (see fig.).
As soon as this interface signal is set to "1", the setting value set by the PLC (DB10,
DBB148 to 163) becomes active for the corresponding analog input. The analog value at the
hardware input or the input disable is then inactive.
Read actual value
The analog values present at the hardware inputs are transferred to the PLC with the
following interface signal:
DB10 DBB194-209 (Actual value of the analog NCK input).
The possible influence of the PLC thus has no effect on the actual value (see figure).
RESET/POWER ON response
After POWER ON and RESET, the analog value at the input is passed on. If necessary, the
PLC user program can manipulate the individual analog NCK inputs via the PLC user
program, as described above.
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Function Manual, 01/2008, 6FC5397-1BP10-3BA0
Extended Functions