Specifications
External
Connections
17.
External Connections
!
Only use shielded cable (see chapter
17.5).
17.1
Interface
RS232C
see chapter
18.
ALARM
B
::/'
Ptl00
17.2
Remote
alarm
Potential free contact with the following pin assign-
ment:
Pin
1
=
make contact
Pin
2
=
middle
Pin
3
=
break contact
Alarm relay in
the
circulator:
The relay contacts
2
and
3
are open in case of an alarm
and when the instrument is switched off.
Rating: max.
30
V
max.
0.1
A
17.3
External
Pt100
sensor
A
sensor in four wire technology is necessary. Only
sensors with shielded wires can be used to fulfill the
EMC
requirements. The shielding must be connected
with the housing of the plug and the sensor shaft.
This sensor has to be connected according to the wiring
diagram.
Pin assignment:
Pin
1
=
current
l
+
Pin
2
=
voltage
U
+
Pin
3
=
voltage
U
-
Pin
4
=
current
I
-
The circulator must be switched off and on again after
inserting an external sensor. The function
EXTERNAL
is otherwise not selectable. The unit switches automat-
ically back to the function INTERNAL.
17.4
110
port
(option!)
This port for analog small voltage will be delivered as
an option and is described separately (see appendix).
17.5
Shielded Cables
In order to keep the electromagnetic noise in the instru-
ment within the tolerable
limitGt is indispensable
to use
only shielded
catles and high quality plug connections.
The complete
contact of the shielding within the plugs
Attach
shielding
plane
is of special importance. Insufficient contact may lead
to noise penetration and result in performance errors.