7.5.2Multi power supply connection to RS232 or RS485 bus
Up to 31 units can be connected (daisy chained) to the RS232 or RS485 bus. The first unit connects to the controller via RS232 or RS485 and the other units are connected via the RS485 bus.
1.First unit connection: Refer to Section 7.5.1 for connecting the first unit to the controller.
2.Other units connection: The other units on the bus are connected via their RS485 interface. Refer to Figure
-Set rear panel setup switch
-Using the Linking cable supplied with each unit (refer to Fig.
connector to the next unit IN connector.
RS232/RS485 | RS485 |
| RS485 |
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| RS485 | ||||||||
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IN | OUT | IN | OUT | IN | OUT | IN | OUT |
POWER SUPPLY | POWER SUPPLY | POWER SUPPLY | POWER SUPPLY | ||||
| #1 |
| #2 |
| #3 |
| #31 |
1 
8 
L=0.5m typ.
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| PIN NO. | NAME | PIN NO. | NAME | |
| HOUSING | SHIELD | HOUSING | SHIELD |
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1 | SG | 1 | SG |
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6 | TXD - | 6 | RXD - |
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3 | TXD + | 3 | RXD + |
| |
| 5 | RXD - | 5 | TXD - |
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| 4 | RXD + | 4 | TXD + |
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8
1
Fig.7-6: Serial link cable with RJ-45 shielded connectors (P/N: GEN/RJ-45)
7.6 COMMUNICATION INTERFACE PROTOCOL
NOTE
The address (ADR n) command must return an “OK” response before any other commands are accepted.
7.6.1 Data format
Serial data format is 8 bit, one start bit and one stop bit. No parity bit.
7.6.2Addressing
The Address is sent separately from the command. It is recommended to add 100msec delay be- tween query or sent command to next unit addressing. Refer to Section 7.8.3 for details.
7.6.3End of Message
The end of message is the Carriage Return character (ASCII 13). The power supply ignores the Line Feed (ASCII 10) character.
7.6.4Command Repeat
The backslash character “\” will cause the last command to be repeated.
7.6.5Checksum
The user may add a checksum (optional) to the end of the command. The checksum is “$” followed by two hex characters. If a command or a query has a checksum, the response will also have one. There is no CR between the command string and the “$” sign.
Example: STT?3A STAT?$7B
7.6.6Acknowledge
The power supply acknowledges received commands by returning an “OK” message. If an error is detected the power supply will return an error message. The rules of checksum also apply to the ac- knowledge.
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