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DRO-550 Construction Guide (rev. 2)
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The edge finder and tachometer connectors are 3.5mm (1/8") stereo plugs. The tip is 5V, the
middle ring is the auxiliary signal, and the inner ring is ground as shown in the following
picture. The tip is 5V to ensure that the auxiliary device is not energized until the plug is fully
inserted.
The RS-232 interface is used for both programming the DRO-550 and for interfacing it to a PC.
The cable is wired as indicated in the table. The connector is a 9 pin female d-sub connector.
RS-232 Signal PCB Pin (J18) Female DB-9 Pin
Tx 1
3
Rx 2
2
Ground 3
5