### Understanding the ACR1 with a TP20 Stylus Changer

Now, if you want to combine the ACR1 with a TP20 rack (a stylus changer), things get slightly more complicated. The ACR1 will switch between the SP600 and the TP20 probe bodies. Once the system picks up the TP20, it will go to the MCR20 rack to pick up an appropriate stylus for it.

Suppose you have 3 separate styli that you wanted to use with the TP20 and that the SP600 is used as a single probe (no stylus changing).

When you define the slots, you might call the SP600 probe "SP600_1", and the TP20 probes with the varied styli attached, you might call "TP20_1", "TP20_2", and "TP20_3".

The slots in the ACR1 probe changer would be defined as:

SLOT1 | SLOT2 | SLOT3 | SLOT4
SP600 | TP2 | TP20_1 | TP200
|  | TP20_2 |
|  | TP20_3 |

The slots in the TP20 stylus changer would be defined as:

SLOT1 | SLOT2 | SLOT3 | SLOT4
TP20_1 | TP20_2 | TP20_3 | empty