Gossen Metrawatt GmbH
13
2.3.1
Constant Current Mode (CC)
Constant current mode has two ranges, the high range (CCH) and the low range (CCL). The high range provides wider test range.
The low range provides better resolution at low current settings.
In CC mode, the load will sink a constant current in accordance with the programmed value regardless of the change of input voltage
(see Figure 2.1). Press
key in basic mode to enter into mode selection and parameter setting menu.
Choose CCH or CCL mode with
▲
and
▼
keys. Input the current level via the Entry keys or the knob with
◄
and
►
keys. Use the
Enter
key for confirmation. The CC mode and parameters can also be set via remote command (MODE CCL, MODE CCH, CURRent
<NRf+>).
Figure 2.1 Constant Current Mode (CC)
2.3.1.1
Setting Ranges
In CC mode low range (CCL), the setting range for the current setpoint is 0 ... 10% of the maximum nominal input current, respectively.
In CC mode high range (CCH), the setting rane for the current setpoint is 0 ... 100% of the maximum nominal input current, respec-
tively.
If the mode is changed when the load’s input is in ON status, the load will be turned off for around 5 milliseconds automatically. For
example: when the load is switched from CCL to CCH, the input will be turned off around 5 milliseconds.
Besides, it is noted that the current setpoint may change with the current level to fit the new range.
Example: the present setting is CCH 10.000 A, when the load is switched from CCH to CCL, the current setpoint level will change to
the maximum level of 4.0000 A (SPL 400-40) for CCL.
2.3.1.2
Immediate Current Level
The immediate current level refers to the current set value in CC mode, which can be programmed via mode selection and parameter
setting menu, or via remote command (CURRent <NRf+>). The immediate current level can also be modified directly with
◄
►
cursor
keys ( ) and the knob.
2.3.1.3
Triggered Current Level
The triggered current level refers to the preset current value, which can become immediate current level automatically when a trigger is
received. If the CC mode and the input are enabled, the input will be updated immediately when a trigger occurs. If the CC mode is not
active, this current level will have no effect on the input until the CC mode becomes active. The triggered current level only can be set
via remote command (CURRent:TRIGgered <NRf+>). Once a current level is triggered, subsequent triggers will become invalid until
another (CURRent:TRIGgered <NRf+>) command is received.
The trigger operation is described in detail in one of the following chapters. The status register of the electronic load can keep track of
pending triggers and other operating conditions, which will be described in detail in the “SPL SCPI Programming Guide”.
2.3.1.4
Transient Current Level
The load will switch between the transient high current level (LevelH) and transient low current level (LevelL) when the transient opera-
tion is enabled. The transient current level can be set in transient operation menu from the front panel, or via remote command
(CURRent:HIGH <NRf+>, CURRent:LOW <NRf+>).
2.3.1.5
Programmable Maximum Current Level
Via a remote command (CURRent:PROTection <NRf+>) a maximum current level can be set 0 ... 100% of the maximum nominal input
current, resp.). If this level is exceeded beyond a programmable time delay (0.001 ... 60 s), an acoustic alarm signal is generated and
the load is switched off. The maximum current level can be programmed in all operating modes.
Input Current
In
put V
o
lt
age
Setpoint Current
V
I
