#### Step 2 - Define the Communications Port (optional)

The ACR1 probe changer needs to be connected to a serial communications port if it is used in Host mode. Before calibration can begin, this communications port (or Comm Port) needs to be identified.

Alternatively, the probe changer can be used in standalone mode, which means it relies on timing to do a change cycle (to deposit and collect hardware from the probe changer). In this case, skip this step and proceed to step 3.

Probe Changer Dialog box - Comm tab

To define the communications port, follow these steps:

1. Select the Comm tab.

2. In the Comm port box, select port 2 (typically if using host mode) or None (if using standalone mode). This will depend on the machine’s configuration. It is possible to use this probe changer in one of these two modes:

   - a) Host mode - In this mode the rack controller is connected via cable to a communications port on the computer. All functions are based on signals between the two. If using host mode, proceed with the steps below.

   - b) Standalone mode - In this mode there is no direct communications with the computer or PC-DMIS. This means that all rack functions are based on timing. Respective modes are configured with the dip switched on the rear of the rack controller(s) and are covered in the Renishaw documentation or in the prints for the specific CMM configuration and are not covered here. If using standalone mode, skip to "Step 3 - Define the Mount Point".

3. Unless otherwise indicated, use the following default settings:

   Baud: 9600

   Parity: Even

   Data bits: 7

   Stop bit: 1

4. Click Apply and then OK to close the dialog box.

5. Restart PC-DMIS to force the new port settings to be read in. This last step is very important. Without restarting PC-DMIS, the system will not work properly when the port settings have been changed.

6. Once PC-DMIS restarts, select Edit | Preferences | Probe Changer to open the Probe Changer dialog box.

In the next step you will define the location your probe body will move to when using the probe changer to switch probe components.

Next Step