Application note

Level alarms on analogue channels

Alarms on analogue channels can be selected as
– AnalogIn higher than Level1
– AnalogIn higher than Level2
– AnalogIn lower than Level1
– AnalogIn lower than Level2.
– No load / Wire broken.

Limit alarm can be enabled to create an alarm signal, when the AnalogIn values are higher and/or lower than the limits specified. Level1 and Level2 alarm conditions can be combined freely, which makes the system very flexible.

No load / Wire broken. When using the analogue channels in 4–20 mA mode, a current monitor can be enabled to produce an alarm if the current drops below 3 mA.

(See also: ChConfig.EnableFunctions)

Example 1:

Alarm used for monitoring “Signal too high” or “Signal too low”:

Example 2:

Alarm used for monitoring “Signal high” or “Signal too high”

Related Topics

Signal out of range alarms
Application note for PD 640 (mA)
Application note for PD 641 / 643 (Pt100 / Pt 1000)
Application note for PD 642 / 643 (mV / thermocouple)
Analogue modules