Siemens SINUMERIK 840D sl Function Manual page 474

Detailed description
2.5 Optimization of the control
Example
Output of the pulse enable of machine axis X1 to the first digital NCK output in all modes
IDS = 1 DO $A_OUT[1] = $VA_DPE[X1]
Supplementary conditions
The functional expansion is available for digital drives in all control variants providing
synchronized actions.
Control response with POWER ON, RESET, REPOS, etc.
After POWER ON, the value 0 is supplied while communication with the drive is not yet
established. Then, the system variable $VA_DPE always specifies the pulse enable value
acquired at the beginning of the interpolation cycle. The modeindependent evaluation or
retransmission should be carried out using static synchronized actions (vocabulary word
IDS).
86
Basic logic functions: Velocities, Setpoint/Actual Value Systems, Closed-Loop Control (G2)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0