The PAC can be paired with Parker P Series servo drives to solve registration or position capture applications. The position capture operation can be accomplished by using the
MC_TouchProbe function block.
MC_TouchProbe requires an axis whose position will be captured (the
Axis input) and information about how the position will be captured (the
Trigger input). The
Trigger input is a
For high-performance position capture,
bFast should always be set to
TRUE. The exact mode of capture can be defined using
iTriggerNumber. The following modes are supported by default:
- Mode 0: Touchprobe 1, rising edge
- Mode 1: Touchprobe 1, falling edge
- Mode 2: Touchprobe 2, rising edge
- Mode 3: Touchprobe 2, falling edge
Once the drive's touchprobe is armed,
MC_TouchProbe will hold its
TRUE until the drive's touchprobe input makes the appropriate transition (rising or falling). Then, the drive will record the current position reported by the motor's encoder and
MC_TouchProbe will report that position in engineering (scaled) units on its
The P Drive's touchprobe inputs can be configured in Drive Support Tool. Any digital input can be set up as a touchprobe input. The PROBE1 and PROBE2 functions define which two digital inputs are to be used as inputs for Touchprobe 1 and 2 respectively. It is not necessary to have both PROBE1 and PROBE2 configured if only one touchprobe is needed for an application. The Digital Input panel in Drive Support Tool can be accessed from the toolbar.
The PROBE1 and PROBE2 functions can be selected from the dropdown menus.
The sample included in this article is a PAM project archive that shows how to use
MC_TouchProbe. It has one P Drive configured in its EtherCAT_Master tree and a small WebVisualization interface to allow the user to experiment with the touchprobe feature. The sample can be downloaded using the link below.