Measurement Functions; Fast Inputs And Outputs; Probe Commissioning - Siemens SINUMERIK 808D ADVANCED Series Commissioning Manual

11

Measurement functions

11.1

Fast inputs and outputs

The fast input/output interface (X21) provides 3 digital inputs and 1 digital output:
Illustration
PLC interface address
DB2900 Signals from fast inputs and outputs [r]
NCK → PLC interface
Byte Bit 7
0
Input 8
4
Output 8
● Fast inputs
In the PLC application program, you can directly read each bit value from the address DB2900. In a part program, you
can read the fast input value via system variable $A_IN[x].
● Fast output
From the address DB2900.DBX4.0 you cannot assign a value to the fast output; otherwise, the PLC application program
will stop with an error. However, you can assign a value to the fast output from address DB2800.DBX5.0 and
DB2800.DBX6.0.
In the PLC application program, you can trigger the address DB2800.DBX5.0 with a rising edge or a negative edge at the
address DB2800.DBX6.0, and thus the address DB2900.DBX4.0 will vary with the address DB2800.DBX6.0.
11.2

Probe commissioning

The first probe is connected to pin 4 (DI1) and the second probe to pin 5 (DI2) of interface X21. For the probe, use an
external voltage (24 V) whose reference potential should be connected to X21 pin 10
Setting machine data
The following machine data should be checked and adjusted if necessary:
● MD13200[0] $MN_MEAS_PROBE_LOW_ACTIVE = 0 or 1
● MD13200[1] $MN_MEAS_PROBE_LOW_ACTIVE = 0 or 1
– Value 0 = deflected state 24 V (default)
– Value 1 = deflected state 0 V
You can access this machine data through the following operations:
+ →
Commissioning Manual
6FC5397-4EP10-0BA8, 07/2018
Pin Signal
4 DI1
5 DI2
6 DI3
7 DO1
Bit 6 Bit 5
Actual value for digital NCK inputs
Input 7 Input 6
Setpoint for digital NCK outputs
Output 7 Output 6
→ →
Variable Description
$A_IN[1] Fast input with address DB2900.DBX0.0, for
connection to probe 1
$A_IN[2] Fast input with address DB2900.DBX0.1, for
connection to probe 2
$A_IN[3] Fast input with address DB2900.DBX0.2
$A_OUT[1] Fast output with address DB2900.DBX4.0
Bit 4 Bit 3
Input 5 Input 4
Output 5 Output 4
Bit 2 Bit 1
Hardware input
Output 3 Output 2
Bit 0
Hardware
output
233