Multi-Power Supply Connection To Rs-232 Or Rs-485 Bus; Communication Interface Protocol; Data Format; Addressing - TDK-Lambda GENESYS GEN 2400W Series Technical Manual

7.4.2

Multi-Power Supply Connection to RS-232 or RS-485 Bus

Up to 31 units can be connected to a RS-232 or RS-485 bus (via a RS-485 daisy-chained serial communication
bus). The first unit connects to the controller via the J3-IN (RS-232 or RS-485) connector and the other units are
connected via the daisy-chained J3-IN/J3-OUT (RS-485) connectors. The user must set all Slave supplies to a
unique unit Address and no two supplies may have the same unit Address.
1. First unit connection: Refer to Section 7.5.1 for connecting the first unit to the controller.
2. Other unit(s) connection: The other units on the daisy-chained serial communication bus are connected
via their RS-485 interface. Refer to Figure 7-5 for a typical multi-power supply connection.
- Set the rear panel setup DIP-switch SW1-6 to the UP position.
- Using the "Linking" cable, supplied with each unit (refer to Figure 7-6), connect each unit J3-OUT
connector to the next unit J3-IN connector.
*It is recommended that when using several power supplies in a serial communication daisy-chain system to
connect a 120ohm resistive termination at the last unit J3-OUT (RS-485) connector.

120Ω (0.5W) between TXD+ and TXD-

120Ω (0.5W) between RXD+ and RXD-
Figure 7-5: Multi-Power Supply RS-232/RS-485 Daisy-Chain Connection
Figure 7-6: Serial "Link" Cable with RJ-45 Shielded Connectors (P/N:GENR45)

7.5 COMMUNICATION INTERFACE PROTOCOL

The address (ADR n) command must return an "OK" response before any
7.5.1

Data Format

Serial data format is 8 bit, one start bit and one stop bit. No parity bit.
7.5.2

Addressing

The unit Address is sent separately from the command. It is recommended to add a 100 millisecond software
delay between a unit query or sent command to next unit addressing. Refer to Section 7.7.3 for details.
7.5.3

End of Message

The end of message is the Carriage Return character (ASCII 13). The power supply ignores the Line Feed
(ASCII 10) character.
7.5.4

Command Repeat

The backslash character "\" will cause the last command to be repeated.
NOTE
other commands are accepted.
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83-517-000 Rev. A