Multichannel Operation
TM-XDOP-01XN 4–11
Multichannel Operation

Multichannel Connections

You may remotely control up to 50 power supplies from one programming
interface (RS-232 or GPIB) by using multichannel addressing if the CANbus
option is installed.
One power supply will be connected to a PC via RS-232 or GPIB. All other power
supplies are connected via CANbus (Controller Area Network) to that unit. SCPI
commands that include a channel address will be sent via the CANbus to the other
power supplies. (Commands with the local address will be executed locally and
will not be sent).
The multichannel address must be appended to the program mnemonic. If no
multichannel address is appended to the program mnemonic, the command is
executed by the local (directly connected) power supply.
Each unit of the network can send and receive commands to and from other units
on the network. It is highly recommended that only one command be sent at a
time. Any RS-232 and GPIB timeout settings should be increased when using
multichannel commands.

CANbus

The CANbus port is a one male, one female DB9 connector to support “daisy
chain” connections. The CAN (Controller Area Network) is an ISO standard
(ISO11898) for a serial communication network. Table 4-5 describes the pin
functions. Pins 1, 4, 8, and 9 are not used. The CANbus is used for
communications in multichannel operation or current sharing (master/slave)
operation, and is part of the optional GPIB/CANbus interface card.
Table 4-5
CANbus Pins
Pin # Function
1 Not used
2 CANLO
3 Ground
4 Not used
5 Ground
6 Ground
7 CANHI
TM-XDOP-01XN.book Page 11 Monday, July 17, 2006 11:19 AM