Operating the Power Supply Locally
3
Series N8700 User’s Guide
49
Analog Programming of Output Voltage and Current
CAUTION
J1 pin 12, pin 22, and pin 23 are internally connected to the negative sense
terminal. Do not reference these pins to any terminal other than the negative
sense terminal, as it may damage the unit.
In Local mode, the output voltage and current is programmed with
the front panel VOLTAGE and CURRENT knobs or over the remote
interface. In Analog mode, the output voltage and current can be
programmed either by an analog voltage or by resistors connected to
the rear panel J1 connector.
The J1 connector also provides monitoring signals for the output
voltage and output current. The programming range and monitoring
signal range can be selected using the SW1 setup switch.
NOTE
With analog programming enabled, you cannot program the output voltage or
current using the front panel knobs or the remote interface. However, you can
read back output voltage or current from the front panel or the remote interface.
Analog Programming Control Terminals
J1 connector pin 8 accepts a TTL signal or an open/short contact
switch (referenced to pin 12) to select between Local or Analog
programming of the output voltage and current. This function is
enabled or disabled by SW1 setup switches 1 and 2.
J1 connector pin 21 is an open collector output that indicates if the
power supply is in Local mode or in Analog mode. To use this output,
connect a pull-up resistor to a voltage source of 30 VDC maximum.
Choose the pull-up resistor so that the sink current will be less than
5mA when the output is in low state.
SW1 switch 1 and 2
J1 pin 8
function
J1 pin 21
signal
Output voltage/
current control
Both Down (default)
No effect
Open
Local
Either one, or both Up
0 or Short
0~0.6V
Analog
1 or Open
Open
Local
1
14
13
25
10
12
8
9
23
22
+
+
CURRENT LIMIT
PROGRAMMING
OUTPUT VOLTAGE
PROGRAMMING
