30
English
9.2
Connection of the hand-held terminal HHT to
field output A12
The FSK version of the power supply unit SIRAX B 811 can
also transmit a frequency modulated digital signal in addition
to the analogue signal and the power supply. Depending on
the version of the power supply unit, connect the hand-held
terminal HHT to the communication output terminal A12 as
shown in either Fig. 9 or 10.
When a hand-held terminal is connected to field
output A12, the voltage across the burden at output
A1 reduces to 10 V. Digital communication requires
a minimum burden at output A1 of 250
Ω
. A 250
Ω
resistor is therefore connected across the output
circuit. If the load of the burden across output A1
already exceeds 250
Ω
, the resistor can be dis-
connected by changing the position of a jumper (see
Section “10.2. Communication connector”). The full
burden voltage of 15 V is then available at output A1
instead of 10 V. Also observe the rules for connecting
to the communication system.
Output A12 is no longer available on this version as a second
measuring output. It is
not
permissible to connect an ammeter
to output A12.
9.3 Communication connector on A1
Depending on the version of the power supply unit, connect
the processor to either Fig. 11 or 12.
The burden of the communication circuit must be at
least 250
Ω
. Also observe the rules for connecting to
the communication system.
9.4
Connection of the hand-held-terminal HHT to
a non-FSK power supply unit SIRAX B 811
This version of the power supply unit is equipped with
connections a3 and c4 which are electrically connected to
connections a1 and c2. Depending on the version of the
power supply unit, connect the hand-held terminal HHT as
shown in either Fig. 7 or 8.
It is important to note the details on the Type
Examination Certificate for the HHT in the case of
power supply units SIRAX types 811-63.0 ... resp.
811-64.0 ..., with intrinsically safe measurement/
supply circuit (Fig. 8). Also observe the rules for
connecting to the communication system.
A two-pole switch must be included in the supply connection
where facility for switching SIRAX B 811 off is desired.
Note:
An external supply fuse must be provided for DC
supply voltage < 125 V.
9.5 Connection of power supply leads
Connect the power supply to pins a20 (
–
~
) and c14 (
+
~
) acc.
to Fig. 6.
10. Configuration
The SIRAX B 811 unit has to be opened before it can be
configured (see Section “8. Withdrawing and inserting the
device”).
10.1 Switching output signals A1 / A12 between the
signal ranges 0…20 mA or 4…20 mA
The range of the outputs can be switched from
0…20 mA to 4…20 mA or vice versa depending on the
positions of jumpers J 202 and J 203 (Fig. 13).
Output signals
Pos. of jumpers
A1 / A12
J 202
J 203
4 … 20 mA
1
1
0 … 20 mA
3
3
10.2 Communication connector
Connect the communication connector to output A1 or
A12 (Fig. 9 to 12). Signals are then transferred in both
directions between the hand-held terminal and the
transmitter via the SIRAX B 811.
When using the field output A12, the 250
Ω
burden
connected across output A12 in the power supply unit
can be switched in and out of circuit with the aid of
jumpers J 204 and J 205 (Fig. 14).
Communication
Pos. of jumpers
connected to:
J 204
J 205
Field output A12*
Integrated 250
Ω
resistor
in circuit
,
the burden at measuring
output A1 is reduced 250
Ω
Choise of A1 output signal
range 0/4 ... 20 mA
Voltage across A1 burden:
10 V
Field output A12*
Integrated 250
Ω
resistor
not in circuit
,
the burden at
measuring output A1 is not reduced.
A1 output signal range
4 ... 20mA only
Voltage across A1 burden:
15 V
Measuring output A1
Output signal range 4 … 20 mA
Voltage across A1 burden:
15 V
*See also “Measuring output” in the Section “5. Technical
data”.
3
1
1
1
3
3
