User manual

56 GMC-I Messtechnik GmbH
5.10.2 Master-Slave Series Connection
Functions
As opposed to direct series connection, master-slave series
connection offers significant advantages:
 Equally suitable for voltage and current regulation
 Output parameters (cumulative output voltage, current limiting,
output on/off) are set entirely by the master device.
 All interconnected KONSTANTERs are equally loaded.
Connection
 Define one power supply as a master device.
 Connect master and slave devices as shown in Figure 5.10.2.
 Connect the output leads to the series circuit phase terminals.
 Balance the individual output voltage values with R
sym
.
 Balancing can be simplified and optimized by combining a fixed
resistor (metallic layer,
T
k
50 ppm / K) and a trimming resistor for R
sym
.
Figure 5.10.2 Wiring for Master-Slave Series Connection
Settings
Initial power-up:
 Do not load the outputs (idle).
 Switch the master on (mains) and configure settings:
SIG1 out
Pon rcl
OUTPUT off
USET = Uset / n Uset: Cumulative output voltage
n: Number of devices
Only valid if nominal data are identical for all
devices, see notes
ISET = Iset Current limit value
 Switch slave 1 on and configure:
trG out
SIG1 out
Pon rcl
USET = 0 V The USET rotary knob can be deactivated if
desired by setting ULIM to 0 V.
ISET > ISET
master
The current setpoint at the slave devices must
be set at least 1% higher than at the master
device, e.g. to maximum.
 Use the same procedure for additional slave devices.
 Press the OUTPUT ON key at the master. All slave outputs are
switched on simultaneously and configured.
 Check output voltage at the KONSTANTER displays.
 Output voltage at each of the slaves can be precisely matched to master
output voltage by adjusting R
sym
. Changes appear immediately at the
respective display.
 Connect the load.
 From this point on, setting and regulation of (cumulative) output
parameters are controlled entirely by the master device.
Power-up after initial settings:
 Devices can be switched on and off in any desired order.
Functional Principle
 The master controls output voltage of the downstream
KONSTANTER (slave 1) via the slave’s voltage control input with
the help of the voltage monitoring signal.
 Slave 1 functions as a master device for the next downstream
slave (slave 2), and so forth.
Cumulative output voltage is thus always proportional to
master output voltage.
The master controls the output on/off status of the slave devices via the
connection from the master SIG1 output ( SIG1 out setting ) to the Slave TRG
input ( trG out setting ).
Notes:
KONSTANTERs with Differing Nominal Values
 The KONSTANTER with the smallest nominal current value must
always be used as the master device.
 The current setting range of the other KONSTANTER must be
limited to this lowest value with the ILIM parameter.
 Slave output voltage Uout corresponds to master output
current Uout as a percentage only, relative to U
nom
.
Example:
General
 If analog interface connector cables and the sensing leads are
longer than 1 meter, shielded cable should be used.
The shield is connected to the ground terminal on the housing or
to OUT.
 The same current value is available from all KONSTANTERs.
For this reason, current measured at the master device is sufficient
for the measurement of load current.
The individual measured voltage values for each of the
interconnected KONSTANTERs must be added together in
order to arrive at cumulative output voltage.
Slave,
Nominal Voltage
R
sym
,
Nominal Value
R
sym
,
Combination
20 V 40 k/ 0.2 W 36 k + 10 k pot
40 V 80 k/ 0.2 W 75 k + 10 k pot
80 V 160 k/ 0.2 W 150 k +20 k pot
SSP KONSTANTER
SSP KONSTANTER
SSP KONSTANTER
+ SENSE
OUT
OUT
SENSE
Analog Interface
SIG1 OUT
SIG2 OUT
TRG IN 
TRG IN 
+15 V
AGND
Uset 
Uset +
Iset +
U-MON
I-MON
+ OUT
+ OUT
Master
Settings
USET = Uset / n
ISET = Iset
OUTPUT on/off
+ SENSE
OUT
OUT
SENSE
Analog Interface
SIG1 OUT
SIG2 OUT
TRG IN 
TRG IN 
+15 V
AGND
Uset 
Uset +
Iset +
U-MON
I-MON
+ OUT
+ OUT
Slave 2
Settings
USET = 0 V
ISET > Iset master
OUTPUT on
Load
R
sym
R
sym
+ SENSE
OUT
OUT
SENSE
Analog Interface
SIG1 OUT
SIG2 OUT
TRG IN 
TRG IN 
+15 V
AGND
Uset 
Uset +
Iset +
U-MON
I-MON
+ OUT
+ OUT
Slave 1
Settings
USET = 0 V
ISET > Iset master
OUTPUT on
Output
Output
Output
= Only required for sensing mode operation
trG out
SIG1 out
trG out
SIG1 out
Master: SSP 120-40 U
nom
40 V I
nom
6 A
Settings: USET : 12 V (30%) ISET :3 A
Slave 1: SSP 120-20 U
nom
20 V I
nom
10 A
Results in Uout :6 V(30%)Iout :3 A
Slave 2: SSP 120-40 U
nom
40 V I
nom
6 A
Results in Uout :6 V(30%)Iout :3 A