User manual

10 GMC-I Gossen-Metrawatt GmbH
Performance After Power on
In the event of mains failure, it’s important to specify which
operating state the device will assume when power is restored.
This may be extremely important if the device is used in long-term
testing applications.
One of the following states can be selected:
– Reset = default setting (0 V, 0 A, output deactivated)
– Standby= last used configuration but with deactivated output
– Recall = last used configuration – same as when the instrument
was last switched off, with
active output if it was active prior to
mains failure
– Recall a device configuration from setup memory
Set Output Voltage and Output Current
Output voltage and output current can also be adjusted using the
rotary encoders or the numeric keypad if desired. The rotary
encoders are used exclusively for adjusting voltage and current.
The decimal place to be changed is selected with the scroll keys.
Additional functions and parameters can be accessed and
adjusted with the keys.
Switching the Input On and Off
The power output can be switched on and off by pressing the
appropriate key, with a computer command or by applying a
signal to the trigger input. When switched off, the output is highly
resistive and is not electrically isolated from the power consumer.
The LED on the key indicates status.
Protection and Additional Functions
A multitude of protection and additional functions have been
integrated, for example:
• Limiting of the setting ranges for voltage and current
• Overvoltage protection (OVP) with adjustable response delay
and reaction
• Overcurrent protection (OCP) with adjustable response delay
and reaction
• Protection in the event of reversed polarity at the sensing leads
• Automatic switching to auto-sensing
• Protection against excessive temperature
• Output protected against reverse polarity
• Front panel control disabling
• Backup battery for device settings memory
• Mains failure detection
• Inrush current limiting
Dynamic Sink
A dynamic sink is activated by the control loops as required for
rapid discharging of the output capacitors.
This allows for short response times when switching to smaller
setpoint values. Depending upon the application, the sink
function can also be disabled.
Auto-Sensing
The device can be switched to sensing mode operation (remote
sensing) in order to compensate for voltage drop at the output
leads. Sensing lead terminals are available to this end at the
analog interface. If the (–) negative sensing terminal is connected
to the negative load point, the device is automatically switched to
sensing mode operation. Maximum compensatable voltage drop
is 1 V per output lead.
Front Panel Control Disabling
The controls can be disabled to prevent unauthorized operation
by pressing the appropriate key, with a computer command or by
applying a signal to the trigger input.
Analog Control Inputs
Voltage and current can also be adjusted by via the control inputs
at the analog interface. A 5 V signal corresponds to 100% of the
respective nominal value.
These inputs can be switched on and off using the keys, or with
computer commands.
The controlled output quantity is the sum of the digital setpoint
value and the specified value at the control input.
This function makes it possible to superimpose these control
signals onto the output quantities.
Monitor Outputs
The actual values for output voltage and current can be
acquired at the monitor outputs as a standardized signal (10 V
corresponds to 100% nominal value).
Trigger Inputs
Two floating trigger inputs are available for controlling device
functions. The following trigger input assignments can be
selected:
– output = Switch the power output on and off
– local lock = Disable controls
– SQS = (sequence step) Step-by-step control of a
stored sequence
– sequence = Start / stop the sequence function
– Analog input = Activate / deactivate the analog control inputs
Signal Outputs
Programmable Control Outputs
The analog interface is equipped with three digital control outputs
for status messages to external monitoring devices, for switching
external components on and off, or for coupling purposes.
The status of these outputs can be defined either directly, or
depending upon the following device statuses:
– Output on or off
– Voltage or current regulation
– Sequence function running or finished
– SSET signal status for the sequence function
– Limit value message for the measuring function (tolerance band)
Min-Max Measured Value Memory
The Min-Max function automatically acquires and saves minimum
and maximum voltage and current values.
Tolerance Band (in combination with Min-Max function)
Measured output values can be continuously compared with
stored upper and lower tolerance band values. Evaluation is
possible via the programmable control outputs.
Memory
The memory function makes it possible to save and recall device
configurations using a battery-backed memory module.
The memory module is equipped with two storage areas:
– Setup memory: 12 memory locations for complete
configurations
– Sequence memory: 1536 memory locations for the following
sequence parameters: voltage setpoint USET, current setpoint
ISET, dwell time TSET and function request FSET, with the
ability to invoke subsequences