INFICON BPG400 ATM to Ultra-High Vacuum Gauge - Manual (Page 42)

42
tina03e1-b (2004-02) BPG400 v1.om
The BPG400-SR has two independent switching functions. A floating relay contact
is available for each switching function (
→ 21). Additionally, the relay contact of
the switching function A is accessible on the RS485 interface connector ( → 24).
The functionality of the switching functions (setting of thresholds and re-
lay operation) depends on the gauges threshold potentiometer settings:
Threshold potentiometer setting Functionality of switching function
≤0.5 Volt 1) • Thresholds defined by stored val-
ues (SL+/–, SH+/–, sent by the
host)
• Hysteresis defined by independent
setting of "+" and "–" values
• Relay operation defined by "+" and
"–" values and sequential order of
data transfer
( → following table)
>0.5 Volt 1) • Thresholds defined by potentio-
meter settings
• Hysteresis = 10% of threshold
• Relays energize when pressure
falls below threshold
(Same as BPG400-SD/SP, → 44)
1) Threshold voltages can be read by the host using the appropriate commands
(
→ 41) or measured on the corresponding pins of the gauges 25 pin D-Sub
connector ( → 21).
4.9.4 Switching Functions
Selecting the Source of the
Threshold Values