Beckman System Gold – 406 A/D module (firmware 3.3) not detected in KARAT 8.0 Auto-Configuration

Hello everyone, I am trying to integrate a Waters 420 conductivity detector into a Beckman System Gold setup using a 406 A/D module. I have two different 406 units, both equipped with firmware version 3.3 (EPROMs verified: VER 3.3 on U121, U122 and U123). My system is connected as follows: PC (KARAT 8.0) ? 406 A/D ? 125 pump ? 168 detector The Gold bus itself works correctly: The 125 and 168 always appear during Auto-Configuration. If I power the 406 OFF, the result is exactly the same. The 406 never appears, with either of the two units. DIP switches checked: DIP 6 = OFF (HPLC mode) DIP 5 only enabled on the last module in the chain The Waters 420 is currently connected through an SS420X A/D interface and works fine, but I would prefer to use the native Beckman 406 A/D module if possible. My questions: Has anyone successfully used a 406 A/D module (firmware 3.x) with KARAT 8.0 and had it appear in Auto-Configuration? Is it common for the RS-485 transceiver on the 406 to fail while the module still powers up and the rest of the Gold bus continues working normally? Is there any additional test to verify RS-485 communication on the 406 beyond measuring A/B on the DB15 connector? Any real-world experience with this module would be very helpful. Thank you in advance. —Benito

Equipment: Module 406 Interface A/D y WATER 420