DayTronic 3500 Series, Instruction Manual

Page: 19 / 122

2.a
T
RANSDUCER
C
ONNECTIONS
2.a.1 T
HE
“S
TANDARD
” A
NALOG
I
NPUT
C
ONNECTOR
All 3500 Series instruments except the Model 3510 Thermocouple Conditioner
and the Model 3578 AC Strain Gage Conditioner use the "standard" Analog
Input Connector. Shown in Fig. 2(b), this connector is located on the rear of the
unit. The number of terminals and the specific terminal assignments will depend
on the model itself.
Referring to the appropriate cabling diagram below, connect the wires of your
transducer cable to the corresponding screw terminals of the Analog Input Con-
nector. To facilitate cable connection, the front (screw-terminal) portion of the
connector may be removed from the rear (pin) portion, which is mounted on the
internal Analog Input Board. Press hard when reinserting the front portion, to
make sure it is fully engaged (the small clips should snap into place on the rear
portion).
The special CONDITIONER CONNECTORS used by the Model 3510 Thermocou-
ple Conditioner and the Model 3578 AC Strain Gage Conditioner are described in
the respective sections below.
PLEASE NOTE: CABLE SIGNAL WIRES OR TWISTED WIRE PAIRS SHOULD
ALWAYS BE PROPERLY SHIELDED, AS INDICATED IN THE CABLING DIAGRAMS.
THIS WILL MINIMIZE THE PRODUCTION OF UNWANTED ELECTRICAL NOISE
FROM CAPACITIVE AND INDUCTIVE EFFECTS.
2.a.2 C
ONNECTING A
T
HERMOCOUPLE TO THE
M
ODEL
3510
The Model 3510 Thermocouple Conditioner's rear Analog Input Board mates
with a special CONDITIONER CONNECTOR (shown in Fig. 2(a) and in Fig. 6,
below), which provides a precision thermistor for reference-junction compensa-
tion. This connector contains a screw-terminal pair labelled "+" and "–." The other
two terminals are not used.
Each TC lead should be directly attached to its corresponding screw terminal (it
should never be soldered). The connector itself is "keyed" by a small plastic
insert embedded between a certain terminal-pin pair, which matches a slot in the
rear Analog Input Board. This prevents the connector from being inadvertently
attached upside-down.
Open the connector housing by removing the four screws that hold it together
(two on each side). Be sure to put back the insulating foam block before
reassembling the connector. It's also a good idea to wrap each cable wire
around the respective strain-relief post.
The "shield" wire of the transducer cable should be soldered to the exposed ter-
minal of the L-shaped GROUND LUG located under the head of one of the con-
nector's two captive screws. This will ensure direct shield contact with the 3510’s
metal case.
Open Thermocouple Detection— In the event of a broken thermocouple wire or
other "open TC" condition, the 3510 will automatically report an indeterminate off-
scale reading—that is, a value well outside the normal range of the TC type for
which it has been set.
2.1
S
ETUP
: C
ONNECTIONS AND
P
OWERUP
2
2.a T
RANSDUCER
C
ONNECTIONS
: M
ODEL
3510