Table of Contents
Advertisement
7.4.2 Multi power supply connection to RS232 or RS485 bus
Daisy-chain up to 31 units can be connected to RS232 or RS485 bus. The first unit connects to the
controller via RS232 or RS485 and the other units are connected with RS485 bus, the user must set
all slave supplies to a unique address. No two supplies may have the same address.
1. First unit connection: Refer to section 7.4.1 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 fig.7-5 for typical connection.
- Set rear panel setup switch SW1-6 to it's UP position
- Using the Linking cable supplied with each unit (refer to Fig.7-6), connect each unit OUT
connector to the next unit IN connector.
* I
t is recommended when using ten or more power supplies in Daisy-chain system to connect a
120 ohm resistive termination at the last unit's RS485 OUT connector.
120
W between TXD and TXD
W, 0.5
120
W between RXD and RXD
W, 0.5
RS232/485
1
8
Serial link cable with RJ-45 shielded connectors (P/N: GEN/RJ45)
Fig.7-6:
7.5 COMMUNICATION INTERFACE PROTOCOL
The address (ADR n) command must return an "OK" response before
any other commands are accepted.
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 Address is sent separately from the command.
It is recommended to add a 100 msec software delay between 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.
7.5.5 Checksum
The user may optionally add a checksum to the end of the command. The checksum is "$" followed by
two hex characters. If a command or a query has checksum, the response will also have one. There is no
CR between the command string and the "$" sign.
Example: STT?$3A
STAT?$7B
7.5.6 Acknowledge
The power supply acknowledges received commands by returning "OK" message. If an error is detected,
the power supply will return an error message. The rules of checksum apply also to the acknowledge.
+
-
+
-
RS485
IN
OUT
IN
POWER SUPPLY
POWER SUPPLY
#1
#2
Fig7-5: Multi power supplies RS232/485 connection
8 PIN CONNECTOR (IN) 8 PIN CONNECTOR (OUT)
PIN NO.
NAME
HOUSING
SHIELD
1
SG
6
TXD
3
TXD
5
RXD
4
RXD
RS485
RS485
OUT
IN
OUT
POWER SUPPLY
#3
L=0.5m typ.
PIN NO.
NAME
HOUSING
SHIELD
1
SG
-
-
6
RXD
+
3
+
RXD
-
-
5
TXD
+
4
+
TXD
NOTE
52
52
RS485
IN
OUT
RS485
120 OHM
POWER SUPPLY
TERMINATION
#31
8
1
Advertisement
Table of Contents
