Endress+Hauser Fieldgate FXA320, Руководство по эксплуатации

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3 Function and System Design Fieldgate FXA320
15 Hauser
3.3 Signal channels
Fieldgate FXA320 has two analog input channels, optionally four binary input channels and a relay
output channel. More details are to be found in Chapter 3.5, System Architecture and Chapter 4,
Installation.
3.3.1 Analog input channels
Two analog input channels allow the connection of two 4...20 mA devices. A switch behind the
front panel allows them to be individually configured to be passive (connected device has own
power supply) or active (Fieldgate powers the connected device).
3.3.2 Binary input channels
Four binary input channels, comprising two blocks of two channels with common ground, are
available as an option. The inputs can be used as follows
• Inputs 1, 2, 3, 4: switching status: L-signal: -3 ... +5 V, H-signal: +15 ... +30 V
• Inputs 1, 3: event counting: measuring range 0 ...12.5 kHz
• Inputs 2, 4: frequency measurement: 4.7 Hz (±1%) ... 12.5 kHz (±4%)
The input channel is configured using the Fieldgate Web server.
3.3.3 Relay output
The relay can be used to signal an alarm or save power:
• Alarm relay
The relay is configured as an alarm relay by not selecting the function "Power Down Devices
between Scan Cycles" on the device set-up page. It closes on power-up and opens on power-
down. The alarm circuit must be wired accordingly.
• Power save
For installations where power saving is at a premium, e.g. solar stations, the device power can
be wired via the relay. The function "Power Down Devices between Scan Cycles" is then
selected by ticking the checkbox, see Chapter 6.3.4. When the device scan is complete, the
relay is opened and the power to the devices is cut. When the next scan is due, the relay closes
and after a short delay to allow the device to power-up, the scan proceeds.