Ae Bus Multidrop Operation; Ae Bus Interface; Addresses And Baud Rates; Figure 7-4. S1 Switch On The Mdxii Rear Panel - Advanced Energy MDX II User Manual

AE BUS MULTIDROP OPERATION

When MDXII units are configured for RS-485 multidrop operation, the differential wire pair
at each end of the network must be terminated with a set of terminating resistors. Each MDXII
unit is shipped with terminating resistors that are installed but not jumpered on the logic board.
If you are connecting an MDXII unit as an "end" node, you will need to configure your unit to
have termination. The following procedures explain how to do this.
Terminating AE Bus
1. Disconnect all sources of input power from the MDXII unit and wait a few minutes before
attempting to set the jumpers.
2. Remove the top cover and the clear plastic safety shields.
3. Pull up on the end of each extractor lever; grasp both levers and use them to remove the
logic PCB from the card cage (the logic PCB is the board closest to the outside of the unit).
4. If RS-485 is used and the MDXII unit is the last node on the multidrop cable, jumper
pins 2 and 3 on headers P10 and P11 (furthest from the silk-screen "TERM"). Otherwise,
leave the jumpers on pins 1 and 2.
5. Return the PCB to the card cage and replace the safety shields and cover.

AE Bus Interface

ADDRESSES AND BAUD RATES

A switch, labeled S1, is located on the rear of the MDXII unit. The S1 switch contains eight
miniature switches ("mini-switches").

Figure 7-4. S1 switch on the MDXII rear panel

5700262-R Serial Port Connection, Controls and Indicators
MDXII Power Supplies
7-5