#### Step 4 - Define Ports

The example described in this documentation has a probe extension in slot 7 and slot 8. When using a probe extension such as these, it must be identified and defined prior to calibration.

To get started defining the ports, select the Slots tab. When the probe rack is first identified, the slots list will show all as UNDEFINED. All slots in the rack must be defined before starting.

Probe Changer dialog box - Slots tab showing undefined slots

To define the ports of your ACR1 Probe Changer, follow these steps:

1. Select TYPE= Autochange from the Active probe changer list.

2. Select a slot from the list and click Edit Slot Data. This opens the Probe Changer Slot Data dialog box.

3. For each slot, you need to classify its contents as either “Probe Attached” or “Extension Only.

1. - Probe Attached – Only probe bodies are in the slots, or the slot is empty.

   - Extension Only – The slot contains a probe extension (Renishaw PEM Autojoint to Autojoint Extension Bar, commonly called PEM). The PEM is available in various lengths, but the length is not significant at this point.

Probe Changer dialog box - Slots tab (showing selection options)

4. Select Probe Attached or Extension Only from the Slot Type list.

5. You may specify the XYZ values for the center position of the port or leave those values empty. In any case, PC-DMIS will automatically populate these values upon successful calibration. See "Step 9 - Review Calibration Results".

6. Click OK to save changes to slot data and close the Probe Changer Slot Data dialog box. Repeat steps 3 through 5 for all ports in your changer.

In the image of the Probe Changer dialog box below, slots 1 through 6 have been defined as containing only a probe body, and slots 7 and 8 are identified as each holding a PEM probe extension. It is not necessary that they be in adjacent slots, this is for illustration purposes only.

Probe Changer dialog box - Slots tab with the slots fully defined

7. Click Apply to save your changes.

You are now ready to begin calibration. In the next step, you will start the calibration procedure.

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