
7
Connections
Front Panel Connections
Appliance Connector
The load under test should be plugged into the front panel appliance connector. Power to the
connector is supplied from the fixed
LOAD POWER
cable via an internal 20A fuse and a relay
which is controlled by the
LOAD
switch. If the
LOAD
switch is in the
OFF
position, or if there is no
instrument power (e.g. the
POWER
switch is
OFF
) then the load power supply is disconnected
from the appliance socket.
A wide choice of national appliance connectors is available but the connector is factory fitted and
cannot be changed by the user. The maximum load current that can be supplied is the rating of
the connector, or 16Arms, whichever is lower.
Voltage and Current Monitor
The Voltage Monitor and Current Monitor BNC sockets output reconstructed, scaled versions of
the load power voltage and current waveforms referenced to instrument ground, permitting direct
connection to other instruments such as an oscilloscope. The output voltage is approximately
2.5V pk-pk for a full-scale signal on any current or voltage range.
Rear Panel Connections
Instrument Power and Load Power
The IEC inlet supplies power for the instrument only; the fixed lead supplies the load power to the
front panel appliance connector. Refer to the Installation section.
USB
The USB interface is intended for communication with a PC running the HA-PC Link Plus
software. See software installation section for information about device driver requirements.
RS232
The RS232 interface should be connected to a standard PC port using a fully wired 1-1 male-
female cable without any crossover connections. It may also be used with a serial printer.
The 9-pin female D-connector has the following pin-out:
Pin
Name
Direction
Description
1
DCD
O
Passively asserted (+10V through 10k
Ω
)
2
TXD
O
Transmitted data to computer
3
RXD
I
Received data from computer
4
DTR
I
Computer can receive
5
GND
Signal ground
6
DSR
O
Passively asserted (+10V through 10k
Ω
)
7
RTS
( I )
Assumed asserted
8
CTS
O
Computer may send
9
RI
No connection
The signal ground is connected to instrument ground. The Baud rate is fixed at 115,200.
Printer
25-way female D-connector configured as a standard parallel (Centronics) printer port. Connect
directly to a suitable printer using a standard shielded cable.