3.3 Channel Switches and LEDs
For each channel of the NHS device there is one “On/Off” switch to turn the channel on and off and there are two LEDs
(“OK” and “HV ON”) to signal status of the channel.
The green LED “OK” signals the general condition of the channel and the yellow LED “HV ON” signals measured output
voltage at the corresponding channel or is flashing shortly every time the user presses the corresponding “On/Off” switch.
Following behaviors are possible:
LED “OK”
LED “HV ON”
Meaning
not illuminated
not illuminated
An error event occurred, the channel cannot be switched on.
not illuminated
illuminated
An error occurred but there is still a measured voltage at the channel.
illuminated
not illuminated
The channel is switched off and can be turned on.
illuminated
illuminated
The channel is turned on and there is output voltage at
the channel.
flashing
The channel is ramping up or down
3.4 Remote Control
The NHS devices offer two remote control interfaces: USB and CAN.
With the USB connector, one NHS can be controlled with the iseg SCPI instruction set. Available control applications are
iseg Terminal and iseg SCPI Control. Please consider the SCPI for NHS Programmers-Guide
(see apenndix)
document for
further details.
With the CAN interface connectors, up to 64 NHR/NHS devices can be controlled on one CAN line. Therefore every device
has to have a unique CAN Bus address, which can be configured in the Device Menu. Please consider
CAN EDCP
Programmers-Guide (see apenndix)
for further details.
3.5 Protection Features
3.5.1 Hardware Limit
The maximum output voltage for all channels (hardware voltage limit) is defined through the position of the
corresponding potentiometer V
max
. The maximum output current for all channels (hardware current limit) is defined
through the position of the corresponding potentiometer I
max
. The greatest possible set value for voltage and current is
given by V
max
– 2% and I
max
– 2%, respectively. The output voltage and current are limited to the specified value. If a limit is
reached or exceeded in any channel the green LED on the front panel turns off.
3.5.2 Safety Loop
A safety loop can be implemented via the safety loop socket (SL) on the front panel.
If the safety loop is active, then an output voltage in any channel is only present if the safety loop is closed and an
external current in a range of 5 to 20 mA of any polarity is driven through the loop. The loop can be activated by removing
the internal jumper. The jumper can be accessed via a ventilation slot on the bottom of the module.
If the safety loop is opened during the operation, the output voltages are shut off without ramp. Furthermore, the
corresponding bits in the „ModuleStatus“ and „ModuleEventStatus“ registers are set (
CAN EDCP Programmers-Guide (see
apenndix)
). After closing the loop again, the „ModuleEventStatus“ register must be reset to turn the channels on again.
By factory setup the safety loop is not active (the corresponding bits are always set). The loop can be activated by
removing the internal jumper. The jumper can be accessed via a ventilation slot on the bottom of the module (see
dimensional drawings for exact position).
NHS – NIM standard High Voltage Power Supply | Last changed on: 01.10.2018 |
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