INFICON BCG450 ATM to Ultra-High Vacuum Triple Gauge - Manual (Page 32)

32
tina40e1-b (2011-04)
The signal: atmospheric pressure reached is made available via a floating n. o.
contact of a photo MOS relay contact at the sensor cable connector (
→ 19) 1) .
Specifications of the n. o. contact:
Load voltage (V
L
) ≤30 V AC/DC
Load current ≤300 mA AC/DC 2)
1
4
Atmospheric pressure
reached
Diode
Load
R
V
2)
U
L
Sensor cable
connector
C
L
2)
1) Contact specifications for fieldbus gauges BCG450-SD/SP can be found in the
section: Technical Data since the (reprogrammed) setpoint relays (SP A/B) are
used (
→ 20, [1] or [2]).
2) In case of capacitive loads, the charging current has to be limited to the max.
current value specified above (e.g. using a current limiting resistor R
v
).
For inductive loads, voltage peaks have to be suppressed by a parallel diode as
shown. To minimize inductance, keep the wiring as short as possible.
The gauges with part number
353-552 and
353-553
have a built-in two-line display with an LCD matrix of 32×16 pixels. The first line
shows the pressure, the second line the pressure unit, the function and possible
errors. The background illumination is usually green, in the event of an error, it
changes to red. The pressure is displayed in mbar (default), Torr or Pa. The pres-
sure unit can be changed via RS232C interface (
→ 33).
Pressure reading
Pressure unit
Function display
(none) Pirani operation
E Emission 25 μA
E . Emission 5 mA
D Degas
4.6.3 Wiring the relay
"Atmospheric Pressure
Reached"
(BCG450)
4.7 Display
(BCG450)
Pressure Display
Function Display