KEPCO EL Series Electronic Load Operator Manual P/N 243-1295 Firmware Version 3.63 through 3.86 - Manual (Page 43)

SERIES EL 070312
3-7
3.11.6 MASTER/SLAVE OPERATING NOTES/CAUTIONS/WARNINGS
Be sure to read and follow the operating instructions described for a single unit and observe all
Cautions and Warnings. A Master/Slave Load configuration is capable of extremely high power
and extremely high currents, thus suitable precautions should be taken when using the Load.
• Use optimal damping (see PAR. 3.14 for setup instructions to optimize damping set-
tings), otherwise use factory default settings.
• Interconnect UUT and Load with cabling designed to minimize inductance. Remember
that rapidly-changing high-currents combined with inductance produces high-voltage
spikes (spikes that can easily damage equipment including the EL Load).
• To minimize spiking and current surges when using computer-controlled remote opera-
tion, the best sequence is:
1. Select Mode (e.g. MODE CURR).
2. Select very low value set point (e.g. CURR 0.2).
3. Engage Load (INPUT ON).
4. Slew Load to desired operating set point (e.g. CURR 105).
3.11.7 MASTER/SLAVE DISCONNECT
Once units have been operated in a Master/Slave configuration, they must be reconfigured to
restore normal standalone operation. This may be accomplished either from the front panel, or
via a computer interface.
From front panel: Turn power off to all units, then remove all master/slave cables. Power up all
units, wait two minutes, then turn power off and then back on to all units.
From computer interface: After three seconds send DIAG:RST to the master unit. Disconnect
all master slave cables within 10 seconds or turn off all slaves within 10 seconds and then dis-
connect the slave cables. If power is not cycled on slaves, send CAL:SLAVEMODE 0 followed
by DIAG:RST to each slave. The DIAG:RST command sends back multiple lines of data with
the last line having ### at end to indicate the Reset is complete. The GPIB and Ethernet options
will be available approximately 2 seconds after receipt of the ###.
3.12 OPERATION VIA COMPUTER INTERFACE
The computer interface (either USB, RS 232 optional GPIB or optional Ethernet) can be used to
operate the load from a remote location using a computer using IEEE 488.2 and SCPI com-
mands. Refer to Appendices A and B, respectively, for a complete list of applicable commands
and queries. The commands INPut 1 (or ON) or OUTput 1 (or ON) are equivalent to using the
LOAD switch on the front panel to engage the load; the commands INPut 0 (or OFF) or OUTput
0 (or OFF) are used to disengage the load. Figure 3-1 illustrates the commands used to set the
load to operate at 100 Amperes from a 12.5-volt source in the Constant Current mode, engage
the load, then disengage the load.
The GPIB interface is a listener and a talker; it can send and receive commands. The factory
default GPIB address is 10; refer to.Appendix B, PAR. B.68 to change it.