Gossen MetraWatt SSP 120 Series, Operating Instructions Manual

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48 GMC-I Messtechnik GmbH
5 Analog Interface
5.1 Connector Pin Assignments
SIG1 OUT, SIG2 OUT (output)

Digital status signal outputs with reference to AGND

SIG1 OUT indicates the status defined by SIG1 txt .

SIG2 OUT indicates the status defined by SIG2 txt .

Signal type Open collector

Max. switching voltage 30 V DC

Max. switching current 20 mA
☞
For a detailed description refer to chapter 5.3.
TRG IN+, TRG IN- (input)

Floating, digital control input for controlling a device function
assigned with
trG txt .

Low signal: – 26 V

U
s
 
1 V

High signal:

4 V

U
s
 
26 V,
I
s
= (U
s
– 2 V) / 1.5 k

☞
For a detailed description refer to chapter 5.8.
+15 V (output)

This auxiliary voltage output (15 to 17 V DC with reference to
AGND) can be used to control the trigger input, or to supply
power to external components (e.g. reference element for
generating control voltages).

The output is equipped with electronic current limiting to
approximately 60 mA, and is short-circuit proof to AGND.
AGND (analog ground = reference point)

Reference point for analogue control inputs and outputs.

This terminal is internally connected to the minus pole of the
power output via an auto-reversible fuse with a rating of
110 mA.
Uset-, Uset+ (input)

Analog (differential) voltage input with reference to AGND for
controlling output voltage. The following applies when the
output is activated:

Uout = USET + U
su

k
u
Uout = Output voltage in constant voltage regulating mode
USET = Voltage setpoint selected in manual mode
U
su
= External control voltage (0 to 5 V 0 ... Uout
nom
)
k
u
= Control coefficient = Uout
nom
/ 5 V
R
su
= Input resistance
(U
set +: 10 k

)
Uset–: 15 k

☞
For a detailed description refer to chapter 5.4.
Iset+ (input)

Analog voltage input with reference to AGND for controlling
output current. The following applies when the output is
activated:

Iout = ISET + U
si

k
i
Iout = Output current in constant current regulating mode
ISET = Current setpoint selected in manual mode
U
si
= External control voltage (0 to 5 V 0 ... Iout
nom
)
k
i
= Control coefficient = Iout
nom
/ 5 V
R
si
= Input resistance : 10 k

☞
For a detailed description refer to chapter 5.5.
U-MON (output)

Analog voltage output signal, proportional to output voltage
Uout acquired by the sensing leads.
(0 ... 10 V 0 ... Uout
nom
).

The short-circuit proof output is referenced to AGND , has an
internal resistance of 9.8 k

and is short-circuit proof .
☞
For a detailed description refer to chapter 5.6.
I-MON (output)

Analog voltage output signal, proportional to output current
(0 to 10 V 0 ... Iout
nom
).

The short-circuit proof output is referenced to AGND , has an
internal resistance of 9.4 k

and is short-circuit proof .
☞
See detailed description in chapter 5.7.
Figure 5.1 Internal Wiring of Analog Interface and Output
(simplified representation)
SIG1 OUT
SIG2 OUT
TRG IN -
TRG IN +
+15 V
AGND
Uset -
Uset +
Iset +
U MON
I MON

SENSE

OUT

OUT
+ SENSE
20
OUT
IN
ADJ
1.5 k


10 k
10 k
10 k

+
9k8
9k4

T
110 mA
+ OUT
+ OUT
+

-
+
-
81
81
120 k
120 k
R
a
R
b


+18 V
U-Reg.
I-Reg.
U-Reg.
I-Reg.
R
a
= R
b
= 60 k for 20 V types
30 k for 40 V types
15 k for 80 V types
ANA
LOG I
N
TERF
A
C
E
OU
TPUT
5 k

P
Controlled
37.5 k for 32 V type