KEPCO EL Series Electronic Load Operator Manual P/N 243-1295 Firmware Version 4.00 to 4.xx - Manual (Page 31)

SERIES EL 071414 2-13
2.6.5.2 ISOLATED EXTERNAL INPUT (SELV)
The 0 to10V input at pin 2 (pin 7 SELV return) of the ANALOG CONTROL connector (see Figure
2-4 for single or Figure 2-5 for dual output models) adjusts the controlled parameter (depending
on mode selection) from 0 to full scale. (NOTE: This signal is not provided on Model EL 3K-25-
400DG). This input is referenced to the chassis via a 100 Ohm resistance, resulting in no possi-
bility of lethal or equipment damaging voltage on the input pins. This SELV input goes from A/D
to D/A conversion leading to slower response than the hazardous input: 60 microsecond tran-
sients can be accommodated rise/fall times of 20-30 microseconds. Refer to PAR. B.96 to
enable or disable this input.
2.6.6 CURRENT MONITOR CONNECTIONS
The output signal (
ILOAD) at pin 1 (pin 6 SELV return) of the ANALOG CONTROL connector
(see Figure 2-4 for single or Figure 2-5 for dual output models) is 0 to 10V, corresponding to 0 to
full scale of the load’s rated current. Monitor current using an external voltmeter connected
across pin 1 and pin 6 when the load is drawing current from the UUT. For Master/Slave config-
urations, each
ILOAD output reflects the current flowing in that individual load.
2.7 DIGITAL CONNECTIONS
When communicating with the Series EL via a computer interface, the Series EL responds to
IEEE 488.2 and SCPI (Standard Commands for Programmable Instruments) commands and
queries. Compatible IEEE 488.2 commands and queries are listed in Appendix A. The complete
list of SCPI commands designed for the Series EL Electronic Load are listed in Appendix B.
2.7.1 STANDARD UNITS
If control via the USB or RS-232 computer interface is desired, the computer should be con-
nected to the load via either the USB 2.0 type B connector or the RS-232 interface connector
located at the rear panel.
For simple communications a terminal emulator program such as HyperTerminal provides the
necessary interface. No drivers are required when using the RS-232 interface, however If USB
communications are used, a special driver must be installed (the USB interface is not plug and
play). Refer to the Kepco website to download the Series EL USB Driver Installation Manual that
describes how to download and install the driver, as well as how to establish communications
between the Series EL load and the computer using a terminal emulator:
www.kepcopower.com/support/opmanls.com#e
NOTE: If using USB and HyperTerminal, it is advisable to first turn on the Series EL load and
then launch HyperTerminal as HyperTerminal may become dysfunctional (hung up) if
power is removed from the USB connection before HyperTerminal is closed or before
the connection is closed.
2.7.2 G OPTION - GPIB INTERFACE
For G option units, connect the EL Load GPIB connector at the rear panel to the GPIB bus using
a standard GPIB cable (not supplied). NOTE: GPIB drivers are not available.
2.7.3 E OPTION - ETHERNET INTERFACE
For E option units, connect a computer to the LAN connector at the rear panel using a standard
RJ 45 Ethernet cable (not supplied). The LAN interface uses a socket connection at Port 5025.