Table of Contents
Advertisement
If a custom cable is used, connect only the pins listed in the table above. Keep pins 1, 2, and 7 not
connected.
When using multiple LAN controllers with Multi-drop, only one power supply may be "selected" at
a time because one controller may change the selected address and the others may not be aware
that a new address is active.
Set the Master Power Supply (First unit)
1.
Set the Master power supply communication interface (RS232, RS485, USB, LAN, or Optional
communication (i.e., IEEE or MODBUS TCP). Refer to section 4.2.2.
2.
Set the supply's RS-485 address as described below. Refer to section 4.2.3.
Set the Slave Power Supply (RS-485 units)
1.
Set the Slave power supply communication interface to RS485. Refer to section 4.2.2.
2.
Set the supply's RS-485 address as described below. Refer to section 4.2.3.
Selecting One Power Supply in a Multi-drop Chain
All the SCPI commands may be sent to any one of the supplies in an RS-485 chain by first sending
the INSTrument:[N]SELect <NR1> address command.
All commands and queries will then apply only to the selected supply, until a new
INSTrument:[N]SELect <NR1> is sent.
After sending INSTrument:[N]SELect <NR1>, it is recommended to verify the command by sending
INSTrument:[N]SELect?, otherwise further commands may go to the wrong power supply.
Global Commands in a Multi-drop Chain
•
The GLOBAL commands affect all the supplies at the same time (Master and Slaves).
•
There is no SYSTEM:ERROR? response message if one or more supplies cannot execute
a global command.
•
There is no query version of these commands. Global settings must be queried by
selecting one power supply at a time and reading its setting.
•
The global commands do not affect which power supply has been selected using the
INSTrument:[N]SELect <NR1> command. For example, if the following commands are
sent:
INST:NSEL 4
VOLT 50
GLOB:VOLT 70
VOLT 90
All the supplies on the multi-drop chain will be set to 70 volts, except for the supply at RS-485
address 4 that will be set to 90 volts.
NOTE
CAUTION
87
Advertisement
Table of Contents
